decreases by a factor of 0.5
John O'Flaherty
What is its new value?
Maybe I just have a mental block tonight, but it seems like it would
decrease to 4 mm. But that's the same as decreasing by a factor of two,
isn't it?
--
john
CyberCypher
W3NID says: factor
5 a : any of the numbers, quantities, or symbols in mathematics that
when multiplied together form a product b : a quantity by which a
measure must be multiplied or divided in order to express it in other
terms; also : a quantity by which a given quantity is multiplied or
divided in order to indicate a difference in measurement c : the
number by which a given time is multiplied in photography to give the
complete time for exposure or development d : a number that converts
by multiplication the weight of one substance into the chemically
equivalent weight of another substance called also gravimetric factor
I immediately thought that to arrive at the correct answer, which would
have to be 4 mm, one would have to multiply the original size by the
factor of decrease, or [8 mm X 0.05 = 4 mm].
--
Franke: EFL teacher & medical editor
For email, replace numbers with English alphabet.
"The only problem with seeing too much is that
it makes you insane." Phaedrus
lightbulb
"CyberCypher" <cyber...@19-16-25-13-01-03.com> wrote in message
news:Xns960A84C12...@130.133.1.4...
> John O'Flaherty wrote on 27 Feb 2005:
>
> > The distance between the plates is 8mm. It decreases by a factor
> > of 0.5.
> > What is its new value?
> > Maybe I just have a mental block tonight, but it seems like it
> > would decrease to 4 mm. But that's the same as decreasing by a
> > factor of two, isn't it?
>
> W3NID says: factor
>
> 5 a : any of the numbers, quantities, or symbols in mathematics that
> when multiplied together form a product b : a quantity by which a
> measure must be multiplied or divided in order to express it in other
> terms; also : a quantity by which a given quantity is multiplied or
> divided in order to indicate a difference in measurement c : the
> number by which a given time is multiplied in photography to give the
> complete time for exposure or development d : a number that converts
> by multiplication the weight of one substance into the chemically
> equivalent weight of another substance called also gravimetric factor
>
> I immediately thought that to arrive at the correct answer, which would
> have to be 4 mm, one would have to multiply the original size by the
> factor of decrease, or [8 mm X 0.05 = 4 mm].
>
Usually when you say you are going to decrease a number by a factor of some
other number, you divide. For example, if you wanted to decrease 25 by a
factor of 5, you would figure 25/5. If you wanted to decrease X by a factor
of 2, you would figure x/2. Therefore, the answer to the original question
would be 16mm, as 8/0.5=16. In order to get 4mm, you would have to decrease
the distance by a factor of 2.
Mike G.
Robert Lieblich
What language is this supposed to be in?
--
Liebs
CyberCypher
> "CyberCypher" <cyber...@19-16-25-13-01-03.com> wrote
>>
>> > factor of 0.5.
>> > What is its new value?
>> > Maybe I just have a mental block tonight, but it seems like it
>> > would decrease to 4 mm. But that's the same as decreasing by a
>> > factor of two, isn't it?
>>
>> W3NID says: factor
>>
>> 5 a : any of the numbers, quantities, or symbols in mathematics
>> that when multiplied together form a product b : a quantity by
>> which a measure must be multiplied or divided in order to express
>> it in other terms; also : a quantity by which a given quantity
>> is multiplied or divided in order to indicate a difference in
>> measurement c : the number by which a given time is multiplied
>> in photography to give the complete time for exposure or
>> development d : a number that converts by multiplication the
>> weight of one substance into the chemically equivalent weight of
>> another substance called also gravimetric factor
>>
>> I immediately thought that to arrive at the correct answer, which
>> would have to be 4 mm, one would have to multiply the original
>> size by the factor of decrease, or [8 mm X 0.05 = 4 mm].
>
> Usually when you say you are going to decrease a number by a
> factor of some other number, you divide. For example, if you
> wanted to decrease 25 by a factor of 5, you would figure 25/5. If
> you wanted to decrease X by a factor of 2, you would figure x/2.
> 8/0.5=16. In order to get 4 mm, you would have to decrease the
> distance by a factor of 2.
That may be standard usage in the math business --- I don't know
anything about math except what I learned in grade school --- and it
certainly makes sense if one thinks that it's necessary to divide the
end result of a multiplication process by one of the factors, viz.
"5" in this case, when the writer says "decreases by a factor of X",
but it certainly doesn't square with the language used, which
suggested to me that a decrease in size was required, and that
implies multiplying a larger number by a decimal, especially when
dividing would provide an increase rather than a decrease.
Bill Walsh takes journalists to task for not being "numerate" when
they write stuff that doesn't agree with standard math usage. But as
educated readers, we have to be able to demonstrate, even if the
writer is not numerate, that we are literate enough to understand
what the writer intended, if the intention is clear enough, which
seems to be the case here.
The obvious fix is to rewrite the original sentence in clear and
simple English that all of us will find unexceptional:
"The distance between the plates is 8 mm. It decreases by 50%."
CyberCypher
Mathish, or its alter ego Numerese. It's certainly not the kind of
language I would let slide by in any of the medical papers I edit.
lightbulb
The question was worded as a math problem. If, in everyday conversation,
somebody asked me that question, I would ask them which they meant,
reduction by a factor of two or by a factor of 0.5. The language used is
the same that would be on any math test that would ask such a question. I
don't think that your rewrite is what the originator of the question had in
mind. John made the distinction in his post that the question was not about
reducing by a factor of two, which he already figured would give the answer
as 4mm. Reduction by a factor of two and reduction by a factor of 0.5 are
not the same thing.
Mike G.
John O'Flaherty
That would have been much clearer.
--
john
John O'Flaherty
It's a problem from a physics book. The answers to the problem indicate
that they mean the distance goes from 8mm to 4 mm. I agree with Franke's
translation to English- it decreases by 50%. Or, they could have said it
decreases by 0.5, which I would see as the same as 50%. The problem is
the 'factor of'.
--
john
lightbulb
"John O'Flaherty" <quia...@yahoo.com> wrote in message
news:38datrF...@individual.net...
> Robert Lieblich wrote:
> > John O'Flaherty wrote:
> >
> >>The distance between the plates is 8mm. It decreases by a factor of 0.5.
> >> What is its new value?
> >>Maybe I just have a mental block tonight, but it seems like it would
> >>decrease to 4 mm. But that's the same as decreasing by a factor of two,
> >>isn't it?
> >
> >
> > What language is this supposed to be in?
>
>
> It's a problem from a physics book. The answers to the problem indicate
> that they mean the distance goes from 8mm to 4 mm.
If that is the case it might be worth writing in the correct answer. Are
the solutions provided by the textbook? Is the physics book the textbook
for a class you (or anybody, for that matter) are currently taking?
Mike G.
don groves
quia...@yahoo.com hath writ:
Factors are multiplicands if I remember my high school algebra
correctly. For instance, the factors of x^2-x-2 are (x+1) and
(x-2), meaning that (x+1) times (x-2) = x^2-x-2. Therefore, it
seems to me correct to say that 0.5 and 8 are "factors" of 4
since 0.5 times 8 = 4.
I say the problem with the problem is the word "decreases". If it
was worded "The distance ... is 8mm and it 'changes' by a factor
of 0.5, what is the new value", there would be no confusion.
--
dg (domain=ccwebster)
John O'Flaherty
I didn't express what I meant very clearly. I thought they meant to go
from 8mm to 4mm, but I wasn't 100% sure. Now that I've gone into the
problem, I'm sure they meant to go from 8mm to 4mm.
--
john
John O'Flaherty
Yes. I'm taking the class, and one part of the answer indicates they
meant it went from 8mm to 4 mm. So far I haven't figured out the whole
problem, so I'm still not 100% sure.
--
john
don groves
groves at dgr...@domain.net hath writ:
Checking after the fact, MWCD Online agrees:
Main Entry: factor Pronunciation Guide
In multiplication, one of two or more numerical or algebraic
components of a product. A whole number's factors are the whole
numbers that divide evenly into it (e.g., 1, 2, 3, 4, 6, and 12
are factors of 12). To factor a counting number means to break it
down into its prime number factors. To factor a polynomial is to
find its prime polynomial factors, a basic procedure for solving
algebraic equations. According to the fundamental theorem of
arithmetic, the prime factorization of any number or polynomial
is unique.
--
dg (domain=ccwebster)
Paul Wolff
<tr...@euronet.nl> writes
>Murray Arnow <ar...@iname.com> wrote:
>
>> don groves <dgr...@domain.net (see sig for domain)> wrote:
>
>> > Factors are multiplicands if I remember my high school algebra
>> > correctly. For instance, the factors of x^2-x-2 are (x+1) and
>> > (x-2), meaning that (x+1) times (x-2) = x^2-x-2. Therefore, it
>> > seems to me correct to say that 0.5 and 8 are "factors" of 4
>> > since 0.5 times 8 = 4.
>> >
>> > I say the problem with the problem is the word "decreases". If it
>> > was worded "The distance ... is 8mm and it 'changes' by a factor
>> > of 0.5, what is the new value", there would be no confusion.
>>
>> (0.5 * 16) mm. The distance decreased by the factor 0.5 is 16 mm.
>
>Which would be an increase, in absolute, common-sense terms.
That is surely the key to resolving any claimed ambiguity. We are told
that the distance decreases. We are told that the factor is one half.
We know that a factor is a multiplier. There is only one simplest
meaningful result consistent with these facts.
If we had instead been given a problem which stated that the distance
increased by a factor of two, who would still be confused?
>
>I don't know whether this is language that varies by professional field,
>or what. But by searching on "decreased by a factor of", I turned up
>examples such as this, where using it in regard to fractions (between 0
>and l) is the "common sense" way -- the result decreases, and it
>decreases by the amount you get when you use the fraction as a factor
>(i.e., multiply by the fraction, not divide).
>
>Example. This page defines terms in calculus:
>
>http://www.math.hmc.edu/calculus/tutorials/transformations/
> The amplitude of the graph is increased by a factor of A if |A| > 1
> and decreased by a factor of A if |A| < 1
>
>I also found the fractional amount written as a percent and as a common
>fraction, which is consistent - decimals, percents, and fractions all
>being the same thing.
>
>http://campus.northpark.edu/math/PreCalculus/Transcendental/Exponential/
>Applications/
> These substances decrease by a constant fraction each moment. For
> example, assume that at a given moment we have a sample of 500 g.
> of a radioactive substance that decreases by a factor of 1/2 each
> week. Note: We usually describe this by saying that it "decays" by
> 50%.
>
>However, I also found the use you are familiar with, the "decreased by a
>factor of 2" sort of thing. Maybe this is a case of engineers vs.
>mathematicians, or something.
>
As long as one is twice the other, and the direction of change is
specified by 'increase' or 'decrease', I suppose it doesn't matter which
side of the equation the factor appears on.
--
Paul
In bocca al Lupo!
Donna Richoux
> don groves <dgr...@domain.net (see sig for domain)> wrote:
> > Factors are multiplicands if I remember my high school algebra
> > correctly. For instance, the factors of x^2-x-2 are (x+1) and
> > (x-2), meaning that (x+1) times (x-2) = x^2-x-2. Therefore, it
> > seems to me correct to say that 0.5 and 8 are "factors" of 4
> > since 0.5 times 8 = 4.
> >
> > I say the problem with the problem is the word "decreases". If it
> > was worded "The distance ... is 8mm and it 'changes' by a factor
> > of 0.5, what is the new value", there would be no confusion.
>
> It is still as confusing. Factor implies the original distance is
> (0.5 * 16) mm. The distance decreased by the factor 0.5 is 16 mm.
Which would be an increase, in absolute, common-sense terms.
I don't know whether this is language that varies by professional field,
or what. But by searching on "decreased by a factor of", I turned up
examples such as this, where using it in regard to fractions (between 0
and l) is the "common sense" way -- the result decreases, and it
decreases by the amount you get when you use the fraction as a factor
(i.e., multiply by the fraction, not divide).
Example. This page defines terms in calculus:
http://www.math.hmc.edu/calculus/tutorials/transformations/
The amplitude of the graph is increased by a factor of A if |A| > 1
and decreased by a factor of A if |A| < 1
I also found the fractional amount written as a percent and as a common
fraction, which is consistent - decimals, percents, and fractions all
being the same thing.
http://campus.northpark.edu/math/PreCalculus/Transcendental/Exponential/
Applications/
These substances decrease by a constant fraction each moment. For
example, assume that at a given moment we have a sample of 500 g.
of a radioactive substance that decreases by a factor of 1/2 each
week. Note: We usually describe this by saying that it "decays" by
50%.
However, I also found the use you are familiar with, the "decreased by a
factor of 2" sort of thing. Maybe this is a case of engineers vs.
mathematicians, or something.
--
Best - Donna Richoux
CyberCypher
>> The obvious fix is to rewrite the original sentence in clear and
>> simple English that all of us will find unexceptional:
>>
>> "The distance between the plates is 8 mm. It decreases by 50%."
>
> The question was worded as a math problem. If, in everyday
> conversation, somebody asked me that question, I would ask them
> which they meant, reduction by a factor of two or by a factor of
> 0.5.
I wouldn't. I'd ask whether the speaker meant 4 mm, which is what I
think the wording means. But maybe you know a lot more about math
than I do. I'd be a bit annoyed that the speaker was jargonating
instead of speaking plain English. You'd be a bit annoyed that the
speaker wasn't using the proper math language. I'd be annoyed that
the speaker thought I'd understand math jargon instead of simple,
clear, plain English. You'd be happy to be able to demonstrate that
you knew the jargon better than the speaker.
> The language used is the same that would be on any math test
> that would ask such a question.
That's fine when talking to students in a math class or talking to
mathematicians, but when toalking to the rest of us, it's nice to
leave math-test English in the drawer with the protractor, the slide
rule, and the calculator. It's not conversational English for us
innumerati.
> I don't think that your rewrite
> is what the originator of the question had in mind. John made the
> distinction in his post that the question was not about reducing
> by a factor of two, which he already figured would give the answer
> as 4mm.
John's question was not about math but semantics: What does the
writer mean? My rewrite provides a clear expression of what the
writer meant. John explains what his question meant in another post.
> Reduction by a factor of two and reduction by a factor of
> 0.5 are not the same thing.
I gather that this is the case, but "reduction by a factor of two" is
not intuitive English either. It's jargon. It shouldn't be used when
speaking with or writing for normal folks, only with and for math
students.
John O'Flaherty
> (0.5 * 16) mm. The distance decreased by the factor 0.5 is 16 mm.
>
Physics for Scientists and Engineers, 5th edition.
Raymond A. Serway & Robert J. Beichner
The problem is #25 in the problems for chapter 26, Capacitance and
Dielectrics.
> Badly worded problems are an unending source of trouble on examinations.
> What you think is understandable to everyone will be misunderstood by
> someone.
Really. A lab practical exam: Find the third lowest frequency of
vibration of the string (n=3).
If it said third _from_ lowest, then it would shift it up one, I think.
And they didn't supply a formula or define n, which could be
wavelengths, half-wavelengths, nodes, or antinodes. I finally guessed
they meant 3 antinodes or half-waves.
> --
> Thank you Dr. Chisholm.
Hunh?
lightbulb
"don groves" <dgr...@domain.net (see sig for domain)> wrote in message
news:MPG.1c8b1f71f...@news.web-ster.com...
There is "increasing by a factor of" and there is "decreasing by a factor
of." If the problem was to find the new value after an increase by a factor
of 0.5, the answer would be 4mm, just as an increase by a factor of 2 would
be 16mm.
Mike G.
CyberCypher
[...]
> factor of." If the problem was to find the new value after an
> increase by a factor of 0.5, the answer would be 4mm, just as an
> increase by a factor of 2 would be 16mm.
Trying to figure out the meaning from the words and numbers used
produces a paradox with a decimal factor. If 8 mm *increases* by a
factor of 0.5 to 4 mm, then it actually *decreases* in value and
doesn't "increase" at all. This is even worse that the diffrerence
between "I {could/couldn't} care less" and "flammable" vs.
"inflammable".
lightbulb
"Paul Wolff" <boun...@two.wolff.co.uk> wrote in message
news:D4tHyPa8afICFwA$@fpwolff.demon.co.uk...
> In message <1gsnes2.dhydox37yvfvN%tr...@euronet.nl>, Donna Richoux
> <tr...@euronet.nl> writes
> >Murray Arnow <ar...@iname.com> wrote:
> >
> >> don groves <dgr...@domain.net (see sig for domain)> wrote:
> >
> >> > Factors are multiplicands if I remember my high school algebra
> >> > correctly. For instance, the factors of x^2-x-2 are (x+1) and
> >> > (x-2), meaning that (x+1) times (x-2) = x^2-x-2. Therefore, it
> >> > seems to me correct to say that 0.5 and 8 are "factors" of 4
> >> > since 0.5 times 8 = 4.
> >> >
> >> > I say the problem with the problem is the word "decreases". If it
> >> > was worded "The distance ... is 8mm and it 'changes' by a factor
> >> > of 0.5, what is the new value", there would be no confusion.
> >>
> >> It is still as confusing. Factor implies the original distance is
> >> (0.5 * 16) mm. The distance decreased by the factor 0.5 is 16 mm.
> >
> >Which would be an increase, in absolute, common-sense terms.
>
> That is surely the key to resolving any claimed ambiguity. We are told
> that the distance decreases. We are told that the factor is one half.
> We know that a factor is a multiplier. There is only one simplest
> meaningful result consistent with these facts.
>
The problem, as worded, does not say the distance decreases. It asks you to
decrease by a factor of 0.5. Suppose you had a problem like this:
The distance between the plates is 8mm. It decreases by a factor of X.
Solve for each value of X.
X=5
X=27
X=2
X=0.5
Now, some people might say that X=0.5 would be a "trick question", but it
operates on the same principle as the other values. The question could
easily be written as an increase by a factor of 0.5. Most people would see
that they should multiply by 0.5, which would give the result 4mm, but do
not see the same principle when the terms "decrease" and "divide" are
present. It is a matter of training the mind to use the appropriate logic
of the specific field.
Mike G.
lightbulb
> lightbulb wrote on 28 Feb 2005:
> [...]
> > There is "increasing by a factor of" and there is "decreasing by a
> > factor of." If the problem was to find the new value after an
> > increase by a factor of 0.5, the answer would be 4mm, just as an
> > increase by a factor of 2 would be 16mm.
>
> Trying to figure out the meaning from the words and numbers used
> produces a paradox with a decimal factor. If 8 mm *increases* by a
> factor of 0.5 to 4 mm, then it actually *decreases* in value and
> doesn't "increase" at all. This is even worse that the diffrerence
> between "I {could/couldn't} care less" and "flammable" vs.
> "inflammable".
>
Not really. "Increase" has a specific function and represents a specific
type of operation, namely multiplication. You can see the same principle
when you figure sales tax. With a bill for $100, how would you figure the
sales tax (not the new total)? Supposing it is 6%, as it is here in
Michigan, most people would multiply by 0.06. Even though you are
multiplying, which in "plain English" would imply an increase, you get a
result of $6. Now, $6 is much less than $100. How can that be? Has our
language failed us? No, indeed. It is just a matter of learning how things
actually work, which is necessary if one is going to be in situations where
answering math-related questions is required.
Mike G.
lightbulb
> lightbulb wrote on 27 Feb 2005:
> > "CyberCypher" <cyber...@19-16-25-13-01-03.com> wrote
> [...]
> >> The obvious fix is to rewrite the original sentence in clear and
> >> simple English that all of us will find unexceptional:
> >>
> >> "The distance between the plates is 8 mm. It decreases by 50%."
> >
> > The question was worded as a math problem. If, in everyday
> > conversation, somebody asked me that question, I would ask them
> > which they meant, reduction by a factor of two or by a factor of
> > 0.5.
>
> I wouldn't. I'd ask whether the speaker meant 4 mm, which is what I
> think the wording means. But maybe you know a lot more about math
> than I do. I'd be a bit annoyed that the speaker was jargonating
> instead of speaking plain English.
It is, in fact, plain English. As I noted, 0.5 and 2 are not the same
number.
> You'd be a bit annoyed that the
> speaker wasn't using the proper math language. I'd be annoyed that
> the speaker thought I'd understand math jargon instead of simple,
> clear, plain English. You'd be happy to be able to demonstrate that
> you knew the jargon better than the speaker.
>
> > The language used is the same that would be on any math test
> > that would ask such a question.
>
> That's fine when talking to students in a math class or talking to
> mathematicians, but when toalking to the rest of us, it's nice to
> leave math-test English in the drawer with the protractor, the slide
> rule, and the calculator. It's not conversational English for us
> innumerati.
The question is from a physics book, which is being used in a physics class;
it is not from an English book or from casual conversation. Therefore, I
imagine the "math-test English" would be SOP.
>
> > I don't think that your rewrite
> > is what the originator of the question had in mind. John made the
> > distinction in his post that the question was not about reducing
> > by a factor of two, which he already figured would give the answer
> > as 4mm.
>
> John's question was not about math but semantics: What does the
> writer mean? My rewrite provides a clear expression of what the
> writer meant. John explains what his question meant in another post.
>
Perhaps the question was about math semantics. How, in fact, do you know
what the writer meant? I would submit that you only "know" what you are
interpreting, same as I am.
Mike G.
Donna Richoux
I'm afraid that all your example shows me is that when it comes to
calculating sales tax, the word "increase" isn't used and wouldn't be
appropriate.
I think there are a fair number of people in the world who realize that
multiplying a number (greater than l) by a fraction (between 0 and l)
results in an answer smaller than the original number.
What I would like to know, Mike G, is whether any of these statements
you are making relate to actual experience in technical or educational
fields. Is any of this ("decrease by a factor of," etc) truly what you
do encounter, or are you just speculating? It's fine to speculate, but
it helps us to know when you're doing that.
My own suspicion is, like many other things in the world, there is no
world-wide standard policy.
Paul Wolff
<ligh...@chartermi.net> writes
>
>"Paul Wolff" <boun...@two.wolff.co.uk> wrote in message
>news:D4tHyPa8afICFwA$@fpwolff.demon.co.uk...
>>
>> that the distance decreases. We are told that the factor is one half.
>> We know that a factor is a multiplier. There is only one simplest
>> meaningful result consistent with these facts.
>>
>
>The problem, as worded, does not say the distance decreases.
Looking at the original post:
"The distance between the plates is 8mm. It decreases by a
factor of 0.5. What is its new value?"
"It" stands for "the distance". The distance decreases.
>It asks you to
>decrease by a factor of 0.5.
It tells you to decrease, not increase (sorry about the repetition -
being emphatic, not petulant).
>Suppose you had a problem like this:
>
>The distance between the plates is 8mm. It decreases by a factor of X.
> Solve for each value of X.
>X=5
>X=27
>X=2
>X=0.5
>
>Now, some people might say that X=0.5 would be a "trick question"
Maybe most people would, but we don't actually know. I personally would
say that the question was internally inconsistent, but that's not a
criticism that should be levelled at the original question.
>, but it
>operates on the same principle as the other values. The question could
>easily be written as an increase by a factor of 0.5.
This use of "increase" to denote a decrease is doing violence to the
language. Or are you intending to change the problem?
>Most people would see
>that they should multiply by 0.5, which would give the result 4mm,
Increasing by a factor of 0.5 introduces another level of ambiguity, as
it could mean increase by 50%. In fact, that would to my mind then be
the proper analysis of its meaning, absent the other parts of the
question with the other X values (but I assume that when you are talking
of re-writing the question as an 'increase' question you are omitting
the other X values). On the other hand, decrease by a factor of 0.5 and
decrease by 50% have identical meanings.
>but do
>not see the same principle when the terms "decrease" and "divide" are
>present.
Sorry, but I don't follow the final clause. The only principle to
follow is to increase or decrease the distance as instructed, using a
multiplier of one-half. If a division instruction is to be mentioned,
its meaning will depend on what is said about it.
>It is a matter of training the mind to use the appropriate logic
>of the specific field.
Skitt
[8 mm X 0.05 = 4 mm].
Oy!
--
Skitt (in Hayward, California)
www.geocities.com/opus731/
John_Kane
I must agree with you Mike. The English, if the author(s) intended the
correct answer to be 4mm is clearly wrong. Probably sloppy writing
that did not get caught by the editing process. Unfortunately this
happens all to often, but is is worse when it is in something like a
Physics text.
Slightly off topic, I have found that an almost essential tool for
reading non-ficiton is a calculator. Mind you, it helps in fiction too
some times. A month or so ago I read about the aftermath of an ice
storm on Canada's west coast: A city had begun to supply road salt to
citizens if they came and picked it up themselves. As I recall the
article in a newspaper about 4,000 people came and picked up roughly
5000 tonnes of salt. I suspect that the reporter or the editor mangled
the material just a bit.
Joel Best in his book Damned Lies and Statistics: Untangling Numbers
from the Media, Politicians, and Activists, University of California
Press (2001) gives a great example of the use of numbers in a very poor
way.
As he says in describing "The Worst Social Statistic Ever"
--------------------------
'The dissertation prospectus began by quoting a statistic--a "grabber"
meant to capture the reader's attention.
.......
So the prospectus began with this (carefully footnoted) quotation:
"Every year since 1950, the number of American children gunned down has
doubled." I had been invited to serve on the Student's dissertation
committee. When I read the quotation, I assumed the Student had made an
error in copying it. I went to the library and looked up the article
the Student had cited. There, in the journal's 1995 volume, was exactly
the same sentence: "Every year since 1950, the number of American
children gunned down has doubled."
This quotation is my nomination for a dubious distinction: I think it
may be the worst--that is, the most inaccurate--social statistic ever."
-----------------------------
Why this is so bad is left as an exercise for the reader (or see
http://www.ucpress.edu/books/pages/9358/9358.intro.html for the
explaination. It is however a horrible error and shows that the student
quoting this statistic had paid no attention to what it actually was
saying.
Unfortuately innumeracy is probably even more widespread than
illiteracy and with the many of the same kind of consequences. If we
combine the two then we have really serious problems of comprehension
and interpretation.
John Kane
Kingston ON Canada
rban...@shaw.ca
<cyber...@19-16-25-13-01-03.com> wrote:
>lightbulb wrote on 28 Feb 2005:
>[...]
>> There is "increasing by a factor of" and there is "decreasing by a
>> factor of." If the problem was to find the new value after an
>> increase by a factor of 0.5, the answer would be 4mm, just as an
>> increase by a factor of 2 would be 16mm.
>
>Trying to figure out the meaning from the words and numbers used
>produces a paradox with a decimal factor. If 8 mm *increases* by a
>factor of 0.5 to 4 mm, then it actually *decreases* in value and
>doesn't "increase" at all. This is even worse that the diffrerence
>between "I {could/couldn't} care less" and "flammable" vs.
>"inflammable".
Blessed are the simple of mind for they shall battle in aue and
struggle with words.
CyberCypher
> CyberCypher wrote:
>
> [8 mm X 0.05 = 4 mm].
>
> Oy!
Okay, so I prefer snake eyes..
[8 mm X 0.5 = 4 mm]
CyberCypher
CyberCypher
[...]
> Now, some people might say that X=0.5 would be a "trick question",
> but it operates on the same principle as the other values. The
> question could easily be written as an increase by a factor of
> 0.5. Most people would see that they should multiply by 0.5,
> which would give the result 4mm, but do not see the same principle
> when the terms "decrease" and "divide" are present. It is a
> matter of training the mind to use the appropriate logic of the
> specific field.
Right. It's jargon or "math English", not everyday conversational
English. It's like an idiom: if you don't know what it means, you can't
figure it out from the sum of its parts.
CyberCypher
>
> "CyberCypher" <cyber...@19-16-25-13-01-03.com> wrote in message
> news:Xns960B14706...@130.133.1.4...
>> lightbulb wrote on 28 Feb 2005:
>> [...]
>> > There is "increasing by a factor of" and there is "decreasing
>> > by a factor of." If the problem was to find the new value
>> > after an increase by a factor of 0.5, the answer would be 4mm,
>> > just as an increase by a factor of 2 would be 16mm.
>>
>> Trying to figure out the meaning from the words and numbers used
>> produces a paradox with a decimal factor. If 8 mm *increases* by
>> a factor of 0.5 to 4 mm, then it actually *decreases* in value
>> and doesn't "increase" at all. This is even worse that the
>> diffrerence between "I {could/couldn't} care less" and
>> "flammable" vs. "inflammable".
>>
>
> Not really. "Increase" has a specific function and represents a
> specific type of operation, namely multiplication.
"Multiplication" is just a fancy word for "addition":
2 x 2 = 2 + 2 = 4
3 x 2 = 2 + 2 + 2 = 6
> You can see
> the same principle when you figure sales tax. With a bill for
> $100, how would you figure the sales tax (not the new total)?
It depends. I can either figure how much sales tax to add by
multiplying the sale price by the tax (usually a number between 0 and
one, e.g., 0.75 (7.5%) in Marin County, California, last time I
checked) and then add that number to the sale price, or I can
multiply the sale price by 1.075 and subtract the sale price from the
total price.
> Supposing it is 6%, as it is here in Michigan, most people would
> multiply by 0.06. Even though you are multiplying, which in
> "plain English" would imply an increase,
Only because "multiply" = "add".
> you get a result of $6. Now, $6 is much less than $100. How can
> that be? Has our language failed us? No, indeed.
It depends on how one looks at it. $6 is the amount of the increase,
so if the cost "increases by a factor of 0.06", then the new price
increases to $106; it increases by $6, but it doesn't "increase to
$6". So the language fails us if we don't know the idiom.
> It is just a matter of learning how things actually work,
> which is necessary if one is going to be in situations
> where answering math-related questions is required.
Exactly: in math or physics class or in the staff lounge at the math
department. If I buy something at a Michigan department store and ask
the person selling it to me how much the sales tax is, and that
person replies with "The cost increases by a factor of 0.06", I'll
figure that the person is a smartass math student trying to impress
me with a sophomoronic demonstratation of what he or she learned in
school today, and I'll ask for the answer in plain English: "The
sales tax is %6, so the total is $106." That's plain English.
Skitt
> I can either figure how much sales tax to add by
> multiplying the sale price by the tax (usually a number between 0 and
> one, e.g., 0.75 (7.5%) in Marin County,
You, obviously, were never taught by a professor such as I once had. Unless
all numbers in a problem were correct, there was no credit. Zip. It taught
me a lot about error-checking.
CyberCypher
[...]
> reading non-ficiton is a calculator. Mind you, it helps in fiction
> too some times. A month or so ago I read about the aftermath of an
> ice storm on Canada's west coast: A city had begun to supply road
> salt to citizens if they came and picked it up themselves. As I
> recall the article in a newspaper about 4,000 people came and
> picked up roughly 5000 tonnes of salt. I suspect that the
> reporter or the editor mangled the material just a bit.
>
> Joel Best in his book Damned Lies and Statistics: Untangling
> Numbers from the Media, Politicians, and Activists, University of
> California Press (2001) gives a great example of the use of
> numbers in a very poor way.
Forty-five years ago I asked my boss to change my wages at the
supermarket from whatever it was to $0.01/day and then double it
every day. I knew then that I could have retired six weeks a
millionaire (when being a millionaire meant something in the USA).
>
> As he says in describing "The Worst Social Statistic Ever"
> --------------------------
> 'The dissertation prospectus began by quoting a statistic--a
> "grabber" meant to capture the reader's attention.
> .......
> So the prospectus began with this (carefully footnoted) quotation:
> "Every year since 1950, the number of American children gunned
> down has doubled." I had been invited to serve on the Student's
> dissertation committee. When I read the quotation, I assumed the
> Student had made an error in copying it. I went to the library and
> looked up the article the Student had cited. There, in the
> journal's 1995 volume, was exactly the same sentence: "Every year
> since 1950, the number of American children gunned down has
> doubled."
>
> This quotation is my nomination for a dubious distinction: I think
> it may be the worst--that is, the most inaccurate--social
> statistic ever." -----------------------------
>
> Why this is so bad is left as an exercise for the reader (or see
> http://www.ucpress.edu/books/pages/9358/9358.intro.html for the
> explaination. It is however a horrible error and shows that the
> student quoting this statistic had paid no attention to what it
> actually was saying.
Right. He ignored the English and didn't do the math, as did the
source of the student's quotation, the original idiot:
[quote]
Where did the article's Author get this statistic? I wrote the
Author, who responded that the statistic came from the Children's
Defense Fund (the CDF is a well-known advocacy group for children).
The CDF's The State of America's Children Yearbook--1994 does state:
"The number of American children killed each year by guns has doubled
since 1950."[1] Note the difference in the wording--the CDF claimed
there were twice as many deaths in 1994 as in 1950; the article's
Author reworded that claim and created a very different meaning.
[/quote
> Unfortuately innumeracy is probably even more widespread than
> illiteracy and with the many of the same kind of consequences. If
> we combine the two then we have really serious problems of
> comprehension and interpretation.
This is not an example of innumeracy but of illiteracy. To translate
"X has doubled since 1950" into "Every year since 1950, X has
doubled" demonstrates a lack of understanding of plain and simple
and, to me at least, unambiguous English. English usually relies on
word order to indicate which words modify which other words. The
error here is akin to saying and writing "I only drink red wine after
giving blood" to mean "I drink red wine only after giving blood" or
"I drink only red wine after giving blood".
CyberCypher
> CyberCypher wrote:
>
>> I can either figure how much sales tax to add by
>> multiplying the sale price by the tax (usually a number between 0
>> and one, e.g., 0.75 (7.5%) in Marin County,
>
> You, obviously, were never taught by a professor such as I once
> had. Unless all numbers in a problem were correct, there was no
> credit. Zip. It taught me a lot about error-checking.
Obviously. 0.075. I'm running on empty this morning and haven't yet
shifted into error-checking mode. I thank you for keeping me honest and
pointing out how very like the CIA's my facts are here.
don groves
at tr...@euronet.nl hath writ:
Very likely. It's easy to suppose that "decreased by a factor of
2" must imply division, but then mathematically, "2" is a
divisor, not a factor.
--
dg (domain=ccwebster)
rban...@shaw.ca
<cyber...@19-16-25-13-01-03.com> wrote:
> rban...@shaw.ca wrote on 28 Feb 2005:
>> On 27 Feb 2005 18:00:20 GMT, CyberCypher wrote:
>>>lightbulb wrote on 28 Feb 2005:
>>>[...]
>>>> There is "increasing by a factor of" and there is "decreasing by a
>>>> factor of." If the problem was to find the new value after an
>>>> increase by a factor of 0.5, the answer would be 4mm, just as an
>>>> increase by a factor of 2 would be 16mm.
>>>
>>>Trying to figure out the meaning from the words and numbers used
>>>produces a paradox with a decimal factor. If 8 mm *increases* by a
>>>factor of 0.5 to 4 mm, then it actually *decreases* in value and
>>>doesn't "increase" at all. This is even worse that the diffrerence
>>>between "I {could/couldn't} care less" and "flammable" vs.
>>>"inflammable".
>>
>> Blessed are the simple of mind for they shall battle in aue and
>> struggle with words.
>
>Please explain yourself.
I think it was a German who remarked that against stupidity even the
gods folded their tents, or something like that. When the stupid
themselves fold their tents and tootle off somewhere else it is not
only the gods who are relieved.
lightbulb
I did include a note that my example was not about finding the new total.
>
> > Supposing it is 6%, as it is here in Michigan, most people would
> > multiply by 0.06. Even though you are multiplying, which in
> > "plain English" would imply an increase,
>
> Only because "multiply" = "add".
Whatever the case may be. I'm just trying to make a point about how plain
descriptivist English cannot be injected into math nomenclature without
causing misunderstandings.
>
> > you get a result of $6. Now, $6 is much less than $100. How can
> > that be? Has our language failed us? No, indeed.
>
> It depends on how one looks at it. $6 is the amount of the increase,
> so if the cost "increases by a factor of 0.06", then the new price
> increases to $106; it increases by $6, but it doesn't "increase to
> $6". So the language fails us if we don't know the idiom.
That is a separate issue completely. The point is not that there is a six
dollar increase, but that it is possible to *multiply* a number like 100 by
another number and end up with a product that is smaller. In the "plain
English" that you seem to want to force onto a physics problem, most people
would associate "multiply" with an increase. Its counterintuitive to the
same degree that dividing 8 by 0.5 is counterintuitive. Counterintuitive
does not equal wrong. I gave an everyday example of that; I simply used
multiplication instead of division. The difference (in plain English) is
the same. Many here seem to have a problem with the idea what they expect
to be a decrease is not actually behaving like a decrease. Well, you can't
just pretend the wording means something else because you don't understand
the correct answer. I gave an everyday example of that; I simply used
multiplication instead of division. The difference (in plain English) is
the same.
>
> > It is just a matter of learning how things actually work,
> > which is necessary if one is going to be in situations
> > where answering math-related questions is required.
>
> Exactly: in math or physics class or in the staff lounge at the math
> department. If I buy something at a Michigan department store and ask
> the person selling it to me how much the sales tax is, and that
> person replies with "The cost increases by a factor of 0.06", I'll
> figure that the person is a smartass math student trying to impress
> me with a sophomoronic demonstratation of what he or she learned in
> school today, and I'll ask for the answer in plain English: "The
> sales tax is %6, so the total is $106." That's plain English.
>
That's all well and good. I would agree that the salesperson is being a
smartass. The fact is, that math and physics place the burden on you to
understand them. It is not the other way around. Are you seriously trying
to suggest that the expression "decrease by a factor of 0.5" should actually
be a multiplication simply because that's the most intuitive, common sense,
plain English way it will be understood? That would be very confusing when
people actually have to solve equations like that for the correct answers.
Language in math and physics has to be very specific. It really is much
plainer than the plain English of which you are so fond.
Mike G.
lightbulb
> In message <B3oUd.11149$YU6....@fe06.lga>, lightbulb
> <ligh...@chartermi.net> writes
> >
> >"Paul Wolff" <boun...@two.wolff.co.uk> wrote in message
> >news:D4tHyPa8afICFwA$@fpwolff.demon.co.uk...
> >>
> >>We are told
> >> that the distance decreases. We are told that the factor is one half.
> >> We know that a factor is a multiplier. There is only one simplest
> >> meaningful result consistent with these facts.
> >>
> >
> >The problem, as worded, does not say the distance decreases.
>
> Looking at the original post:
> "The distance between the plates is 8mm. It decreases by a
> factor of 0.5. What is its new value?"
> "It" stands for "the distance". The distance decreases.
>
> >It asks you to
> >decrease by a factor of 0.5.
>
> It tells you to decrease, not increase (sorry about the repetition -
> being emphatic, not petulant).
Right back atcha, babe. I'm definitely sticking to my guns on this one.
You're misunderstanding the language. "Decrease by a factor of X" means you
must divide by X, even if doing so results in a larger number.
>
> >Suppose you had a problem like this:
> >
> >The distance between the plates is 8mm. It decreases by a factor of X.
> > Solve for each value of X.
> >X=5
> >X=27
> >X=2
> >X=0.5
> >
> >Now, some people might say that X=0.5 would be a "trick question"
>
> Maybe most people would, but we don't actually know. I personally would
> say that the question was internally inconsistent, but that's not a
> criticism that should be levelled at the original question.
>
> >, but it
> >operates on the same principle as the other values. The question could
> >easily be written as an increase by a factor of 0.5.
>
> This use of "increase" to denote a decrease is doing violence to the
> language. Or are you intending to change the problem?
Violence to the language? Have you never multiplied a positive number by a
number that is equal to or greater than zero and less than one? I'm not
trying to change the problem, you are. You're trying to multiply by 0.5 to
get 4mm, which is not what the language of the problem is asking you to do.
If you want the answer to be 4mm, you'll have to change the problem to read
"increase by a factor of 0.5" or "decrease by a factor of 2." That is
purity of language.
>
> >Most people would see
> >that they should multiply by 0.5, which would give the result 4mm,
>
> Increasing by a factor of 0.5 introduces another level of ambiguity, as
> it could mean increase by 50%. In fact, that would to my mind then be
> the proper analysis of its meaning, absent the other parts of the
> question with the other X values (but I assume that when you are talking
> of re-writing the question as an 'increase' question you are omitting
> the other X values). On the other hand, decrease by a factor of 0.5 and
> decrease by 50% have identical meanings.
No they do not have identical meanings. That is the point of this
discussion. Pretend you were graphing the altitude of the flight of a
balloon over time. After awhile, the balloon starts to come back down.
Then, a giant wind storm kicks up and the balloon increases in altitude. If
you were given the task of charting the progress of the balloon, and you
were supposed to write down the factor by which the balloon's altitude had
changed since the previous five minute mark, what would you do when the
balloon goes back up if you had to use the language "decreased by a factor
of?" Would you say it was impossible and fail the assignment? You can't go
changing the reality because its counterintuitive.
>
> >but do
> >not see the same principle when the terms "decrease" and "divide" are
> >present.
>
> Sorry, but I don't follow the final clause. The only principle to
> follow is to increase or decrease the distance as instructed, using a
> multiplier of one-half. If a division instruction is to be mentioned,
> its meaning will depend on what is said about it.
Again, the problem as stated does not tell you to decrease the distance.
You can't leave out the rest of the expression, as I pointed out in the post
to which you replied.
Mike G.
lightbulb
"Donna Richoux" <tr...@euronet.nl> wrote in message
news:1gsnqe7.o1ftm1s8zme5N%tr...@euronet.nl...
The example was just to show that trying to apply what some here are
referring to as "plain English" to a
special case situation doesn't always work. I provided an example that was
fairly commonplace and used the same sort of logic. As I said, in the case
of "increase by a factor of", "increase" implies multiplication. The
example I gave involves multiplication. Therefore, it is appropriate for
the purposes for which it was intended, and that is to show that people
routinely perform counterintuitive, non-"plain English" math.
> I think there are a fair number of people in the world who realize that
> multiplying a number (greater than l) by a fraction (between 0 and l)
> results in an answer smaller than the original number.
>
> What I would like to know, Mike G, is whether any of these statements
> you are making relate to actual experience in technical or educational
> fields. Is any of this ("decrease by a factor of," etc) truly what you
> do encounter, or are you just speculating? It's fine to speculate, but
> it helps us to know when you're doing that.
I made it through Calculus in college. Its been a few years,
so I probably couldn't do any Calculus without a refresher course. This
example only involves very simple math skills, and could be performed, sans
physics context, by most 12 or 13 year olds. As for the terminology, I
double checked with a few sites online, which concurred with my
understanding of the situation, before offering my opinion. In a brief
search through the few math textbooks I own, I did not find that particular
phrase. I do not use that terminology in my line of work, although I do
frequently work with fractions. If anybody is still unconvinced that
multiplying and dividing 8 by 0.5 shouldn't give the same answer, I may not
be able to help any further on this matter.
>
> My own suspicion is, like many other things in the world, there is no
> world-wide standard policy.
Perhaps not, but in the same sense that you want to keep your eggcorns to a
certain strict definition, a definition which to me would exclude "eggcorn"
as an
eggcorn, these mathematical terms shouldn't be interpreted and used as
something they don't mean, especially if there are resources available to
help understand the wording. When a misunderstanding takes place, it helps
to correct the usage. I'm not trying to open up a general prescriptivist
vs. descriptivist argument. Math and science don't often follow the same
trends in their nomenclature as society does in general with its usage of
"plain" English. In fact, I don't see how the proponents of "plain English"
are ignoring the fact that "increase by a factor of" means multiply and
"decrease by a factor of" means divide. How much plainer can the language
be?
Mike G.
Here is one example from the many I found through Google.
http://www.physicsclassroom.com/mmedia/momentum/fcb.html
That is, if the amount of mass in motion increases by a factor of two, then
the velocity would decrease by a factor of two (divide the original velocity
by two). If the amount of mass in motion increases by a factor of five, then
the velocity would decrease by a factor of five (divid the original velocity
by five).
lightbulb
<rban...@shaw.ca> wrote in message
news:sv85211v3hq1ggvue...@4ax.com...
You could only find gods with a lower case <g>? Any fool can recognize when
something isn't working. Not every fool can figure out what to do about it.
Do you think the entire issue is stupid, or are both sides missing the big
picture, in your opinion?
Mike G. <-----will be folding his tent on this issue soon anyway
lightbulb
"don groves" <dgr...@domain.net (see sig for domain)> wrote in message
news:MPG.1c8c407af...@news.web-ster.com...
You're dividing the factor out, hence the "decrease." It was a factor; now
its not.
Mike G.
Jordan Abel
>> > The question was worded as a math problem. If, in everyday
>> > conversation, somebody asked me that question, I would ask them
>> > which they meant, reduction by a factor of two or by a factor of
>> > 0.5.
>>
>> I wouldn't. I'd ask whether the speaker meant 4 mm, which is what I
>> think the wording means. But maybe you know a lot more about math
>> than I do. I'd be a bit annoyed that the speaker was jargonating
>> instead of speaking plain English.
>
> It is, in fact, plain English. As I noted, 0.5 and 2 are not the same
> number.
But when using "decreased by a factor of N", the only interpretation
that doesn't lead to something increasing is that numbers are considered
equivalent their reciprocals
don groves
ligh...@chartermi.net hath writ:
Where is the "factor" in (0.8)/2? There are a "dividend" (0.8)
and a "divisor" (2), but no "factor" in this equation.
--
dg (domain=ccwebster)
Jordan Abel
But if you start with the word "increase", the simple undeniable fact is
that the number you want to end up with is $106 - to say "increase by a
factor of 6%" means "multiply by 1.06", period. you wouldn't use the
word "increase" to start with if the number you want is the amount of
the tax.
lightbulb
"Jordan Abel" <jma...@purdue.edu> wrote in message
news:slrnd25f5l...@localhost.localdomain...
Why are you concerned about something increasing? What if it did increase?
What if that was the whole point? Perhaps something was decreasing, so that
was the language being used, and then the factor by which it decreased was
measured at 0.5, indicating an increase? Math does offer its share of
bullshit, like imaginary numbers. But setting a number equal to its
reciprocal? Perhaps there are cases out there where it would make sense to
do that. I don't have enough authority to say that would never happen. But
I do know that with such little context given, it is very possible that the
two plates moved away from each other, and wording like that would be
exactly the type of thing a textbook or teacher would throw at a student to
see if they are paying attention.
Mike G.
lightbulb
Was the point of my example really that vague? I've responded to this
criticism in other posts to this thread.
Mike G.
lightbulb
Okay, you got me. I was being a little silly. If I followed your argument
to the logical conclusion, the English language would have to completely rid
itself of the expression "decrease by a factor of" because there are no
factors, as such, in play. After this thread, I'm not so sure that's not a
good idea.
Mike G.
Carmen L. Abruzzi
> lightbulb wrote:
>
>> "John O'Flaherty" <quia...@yahoo.com> wrote in message
>> news:38datrF...@individual.net...
>>
>>> Robert Lieblich wrote:
>>>
>>>> John O'Flaherty wrote:
>>>>
>>>>
>>>>> The distance between the plates is 8mm. It decreases by a factor of
>>>>> What is its new value?
>>>>> two,
>>>>> isn't it?
>>>>
>>>>
>>>>
>>>> What language is this supposed to be in?
>>>
>>>
>>>
>>> It's a problem from a physics book. The answers to the problem indicate
>>> that they mean the distance goes from 8mm to 4 mm.
>>
>>
>>
>> If that is the case it might be worth writing in the correct answer. Are
>> the solutions provided by the textbook? Is the physics book the textbook
>> for a class you (or anybody, for that matter) are currently taking?
>
>
> Yes. I'm taking the class, and one part of the answer indicates they
> meant it went from 8mm to 4 mm. So far I haven't figured out the whole
> problem, so I'm still not 100% sure.
Why in the world are they presenting you with this initial question in
the first place? Surely they don't think that they're going to trip up
physics students with elementary arithmetic. Why don't they just say
that the distance decreases to four millimeters and get on with the physics?
Paul Wolff
<ligh...@chartermi.net> writes
>
>"Paul Wolff" <boun...@two.wolff.co.uk> wrote in message
>news:1AJK8SCs...@fpwolff.demon.co.uk...
>> In message <B3oUd.11149$YU6....@fe06.lga>, lightbulb
>> <ligh...@chartermi.net> writes
>> >
>> >"Paul Wolff" <boun...@two.wolff.co.uk> wrote in message
>> >news:D4tHyPa8afICFwA$@fpwolff.demon.co.uk...
[Some snipping here and there, hopefully not unfairly]
>> "The distance between the plates is 8mm. It decreases by a
>> factor of 0.5. What is its new value?"
>>
>> It tells you to decrease, not increase (sorry about the repetition -
>> being emphatic, not petulant).
>
>Right back atcha, babe. I'm definitely sticking to my guns on this one.
>You're misunderstanding the language. "Decrease by a factor of X" means you
>must divide by X, even if doing so results in a larger number.
>
I guess we could give up at this point, but I'd like another go.
I can see we have a very basic disagreement. I say that the words
'increase' and 'decrease' have the overriding meaning in the problem as
stated, and that meaning is 'make greater' or 'make smaller'
respectively, and that the factor is placed on the left or right of the
equation accordingly:
Distance[start] * Factor = Distance[finish] [A]
or Distance[start] = Distance[finish] * Factor [B]
and that it is up to the reader to decide based on the instruction to
increase or to decrease, and whether the so-called factor is more or
less than one;
and you say the word 'factor' has the overriding meaning, and that
meaning is 'multiply', and that 'increase' is to be decoded as an
instruction to use equation [A], and that 'decrease' is to be decoded as
an instruction to use equation [B], irrespective of whether an 'increase
distance' instruction gives a smaller distance as a result or a
'decrease distance' instruction gives a greater distance as a result.
So who's misunderstanding the language? He who says 'increase' means to
make greater, or he who says 'increase' means to multiply, even if the
multiplier is less than unity?
>> >The question could
>> >easily be written as an increase by a factor of 0.5.
>>
>> This use of "increase" to denote a decrease is doing violence to the
>> language. Or are you intending to change the problem?
>
>Violence to the language? Have you never multiplied a positive number by a
>number that is equal to or greater than zero and less than one? I'm not
>trying to change the problem, you are. You're trying to multiply by 0.5 to
>get 4mm, which is not what the language of the problem is asking you to do.
The language of the problem is asking you to work out how to make 8mm
smaller using a factor of 0.5 and leaving you to decide that 'by a
factor of 0.5' can only mean, in the context, multiply by 0.5.
>If you want the answer to be 4mm, you'll have to change the problem to read
>"increase by a factor of 0.5" or "decrease by a factor of 2." That is
>purity of language.
>
You won't be surprised if I disagree. If that's what you want, why not
just come right out with it and say 'multiply by a factor of 0.5' or
'divide by a factor of 0.5' in the problem? There is no purity of
language in asserting that 'increase' must be read as 'multiply' and
that 'decrease' must be read as 'divide', when the logical consequence
of that assertion is that 'increase the distance' must then be allowed
to mean 'become closer together' and 'decrease the distance' must be
allowed to mean 'become farther apart'.
Instead, it is made a little harder (it is a test, after all) by leaving
it to the testee to work out for himself whether the problem demands
multiplying or dividing. The testee has to choose between equation [A]
and equation [B].
>>On the other hand, decrease by a factor of 0.5 and
>> decrease by 50% have identical meanings.
>
>No they do not have identical meanings. That is the point of this
>discussion.
I accept that their meanings are not identical in every possible sense.
I meant only that they give identical results with the figures stated.
In arithmetic terms, there is an identity between 50% and 0.5.
>Pretend you were graphing the altitude of the flight of a
>balloon over time. After awhile, the balloon starts to come back down.
>Then, a giant wind storm kicks up and the balloon increases in altitude. If
>you were given the task of charting the progress of the balloon, and you
>were supposed to write down the factor by which the balloon's altitude had
>changed since the previous five minute mark, what would you do when the
>balloon goes back up if you had to use the language "decreased by a factor
>of?" Would you say it was impossible and fail the assignment?
So the question is something like 'State the factor by which the
altitude changes during each five minute interval, expressed as a
decrease'? If the balloon first dropped from 10,000 feet to 8,000 feet,
I would answer 0.2. If it then rose back to 10,000 feet in the next
five minutes, I would follow with -0.25.
>You can't go
>changing the reality because its counterintuitive.
>
>
>Again, the problem as stated does not tell you to decrease the distance.
>You can't leave out the rest of the expression, as I pointed out in the post
>to which you replied.
I hope I do know what your view is, but that I believe it's too rigid
and prescriptive an analysis; it's not necessary to insist that the
problem as stated can't be read to mean what it evidently does mean.
CyberCypher
> "CyberCypher" <cyber...@19-16-25-13-01-03.com> wrote
>> lightbulb wrote on 28 Feb 2005:
>> > "CyberCypher" <cyber...@19-16-25-13-01-03.com> wrote
>> >> [...]
> Whatever the case may be. I'm just trying to make a point about
> how plain descriptivist English cannot be injected into math
> nomenclature without causing misunderstandings.
I think we may be talking at cross purposes here. You're talking
about math and physics language and I'm talking about civilian
language. I have no problem with the way math and physics
professionals use their language to talk about their subjects amongst
themselves or to their students. Specialized language is necessary in
every field.
You're talking about language in a textbook. I didn't even realize
that this language came from a textbook until I read that it had one
or two posts ago. I also failed to read and think critically enough
when looking at what John posted. I looked at "decrease" and assumed
that the question implied that the distance between plates actually
grew smaller (for some unstated reason or other), but as you pointed
out in another post here, without knowing the full context of the
problem presented to the textbook user, the intent of the question
could have been to test whether the reader was paying attention.
I don't think there is any reason to argue about the way the language
is used and what it means in math or physics. I can't argue about
that because I don't know about that. My only point was that it's not
everyday clear language written for those of us who don't have
special knowledge of the math and physics idiom used in that problem.
Medical publishers advise their authors to avoid laboratory and
operating-room jargon when they write for publication, and to
remember, when they write their articles, that their readers don't
always have all the specialized knowledge about the field that the
authors have. Therefore, they say, use clear, plain, simple, easy-to-
understand English whenever possible. There is no advice to avoid the
specialized language of the field if it's necessary. The reader can
always go to a dictionary.
CyberCypher
> On 28 Feb 2005 00:40:27 GMT, CyberCypher wrote:
[...]
>>> Blessed are the simple of mind for they shall battle in aue and
>>> struggle with words.
>>
>>Please explain yourself.
>
> I think it was a German who remarked that against stupidity even
> the gods folded their tents, or something like that. When the
> stupid themselves fold their tents and tootle off somewhere else
> it is not only the gods who are relieved.
You have only obfuscated your point by elaborating. Who are you calling
stupid and why?
K. Edgcombe
>>>>>
>>>>>> The distance between the plates is 8mm. It decreases by a factor of
>>>>>> 0.5.
>>>> that they mean the distance goes from 8mm to 4 mm.
>that the distance decreases to four millimeters and get on with the physics?
"Halved" is a jolly useful word.
Katy
Donna Richoux
> lightbulb wrote on 28 Feb 2005:
> [...]
> > Whatever the case may be. I'm just trying to make a point about
> > how plain descriptivist English cannot be injected into math
> > nomenclature without causing misunderstandings.
>
> I think we may be talking at cross purposes here. You're talking
> about math and physics language and I'm talking about civilian
> language. I have no problem with the way math and physics
> professionals use their language to talk about their subjects amongst
> themselves or to their students. Specialized language is necessary in
> every field.
>
> You're talking about language in a textbook. I didn't even realize
> that this language came from a textbook until I read that it had one
> or two posts ago. I also failed to read and think critically enough
> when looking at what John posted. I looked at "decrease" and assumed
> that the question implied that the distance between plates actually
> grew smaller (for some unstated reason or other), but as you pointed
> out in another post here, without knowing the full context of the
> problem presented to the textbook user, the intent of the question
> could have been to test whether the reader was paying attention.
Except that Mike G. is in the minority here, and most of us appear to
hold the position that "to decrease by" actually must mean to decrease.
No matter what words and numbers follow it ("factor," fractions, whole
numbers) the actual amount in question must decrease. The phrase
following the word decrease tells you how *much* it decreased by.
The main problem is that it appears that some people write the factor as
a whole number, and some people write the factor as its reciprocal (a
fraction), but in this case, they mean the same. Dividing by a whole
number is the same as multiplying by its reciprocal. So if it says
"decreased by a factor of 3" you divide by three (which is multiplying
by one-third), and if it says "decreased by a factor of l/3" you
multiply by one-third.
--
Best -- Donna Richoux
lightbulb
Outside of a classroom exercise, I would stipulate to the fact that most
people would use "increase" when there is an increase and "decrease" when
there is a decrease in this type of problem and use the corresponding
factor. If you want to inject a measure of subjectivity in the matter, you
will have to do so as a disclaimer or part of the instructions when using
this language.
>
> and you say the word 'factor' has the overriding meaning, and that
> meaning is 'multiply', and that 'increase' is to be decoded as an
> instruction to use equation [A], and that 'decrease' is to be decoded as
> an instruction to use equation [B], irrespective of whether an 'increase
> distance' instruction gives a smaller distance as a result or a
> 'decrease distance' instruction gives a greater distance as a result.
>
> So who's misunderstanding the language? He who says 'increase' means to
> make greater, or he who says 'increase' means to multiply, even if the
> multiplier is less than unity?
We're not talking about the word "increase" sitting all alone by itself. It
is being used in a specialized context where it ought to have a specific
function which defines it.
>
> >> >The question could
> >> >easily be written as an increase by a factor of 0.5.
> >>
> >> This use of "increase" to denote a decrease is doing violence to the
> >> language. Or are you intending to change the problem?
> >
> >Violence to the language? Have you never multiplied a positive number by
a
> >number that is equal to or greater than zero and less than one? I'm not
> >trying to change the problem, you are. You're trying to multiply by 0.5
to
> >get 4mm, which is not what the language of the problem is asking you to
do.
>
> The language of the problem is asking you to work out how to make 8mm
> smaller using a factor of 0.5 and leaving you to decide that 'by a
> factor of 0.5' can only mean, in the context, multiply by 0.5.
We're going to have to agree to disagree on this one. I've stated my view
in full on it several times in this thread. You're focusing on "decrease"
and I'm focusing on "decrease by a factor of.'' Its evident that we have
different priorities when interpreting math problems.
>
> >If you want the answer to be 4mm, you'll have to change the problem to
read
> >"increase by a factor of 0.5" or "decrease by a factor of 2." That is
> >purity of language.
> >
> You won't be surprised if I disagree. If that's what you want, why not
> just come right out with it and say 'multiply by a factor of 0.5' or
> 'divide by a factor of 0.5' in the problem?
Maybe to see if the students are paying attention? I'm not trying to be
flippant, but it wouldn't be the first time that has happened.
> There is no purity of
> language in asserting that 'increase' must be read as 'multiply' and
> that 'decrease' must be read as 'divide', when the logical consequence
> of that assertion is that 'increase the distance' must then be allowed
> to mean 'become closer together' and 'decrease the distance' must be
> allowed to mean 'become farther apart'.
>
> Instead, it is made a little harder (it is a test, after all) by leaving
> it to the testee to work out for himself whether the problem demands
> multiplying or dividing. The testee has to choose between equation [A]
> and equation [B].
>
> >>On the other hand, decrease by a factor of 0.5 and
> >> decrease by 50% have identical meanings.
> >
> >No they do not have identical meanings. That is the point of this
> >discussion.
>
> I accept that their meanings are not identical in every possible sense.
> I meant only that they give identical results with the figures stated.
>
> In arithmetic terms, there is an identity between 50% and 0.5.
I agree with that. What I didn't agree with was an identity between
"decrease by a factor of 0.5" and "decrease by 50%." I would agree to an
identity between "decrease by 50%" and "decrease by a factor of 2."
>
> >Pretend you were graphing the altitude of the flight of a
> >balloon over time. After awhile, the balloon starts to come back down.
> >Then, a giant wind storm kicks up and the balloon increases in altitude.
If
> >you were given the task of charting the progress of the balloon, and you
> >were supposed to write down the factor by which the balloon's altitude
had
> >changed since the previous five minute mark, what would you do when the
> >balloon goes back up if you had to use the language "decreased by a
factor
> >of?" Would you say it was impossible and fail the assignment?
>
> So the question is something like 'State the factor by which the
> altitude changes during each five minute interval, expressed as a
> decrease'? If the balloon first dropped from 10,000 feet to 8,000 feet,
> I would answer 0.2. If it then rose back to 10,000 feet in the next
> five minutes, I would follow with -0.25.
>
In your view "decrease by a factor of" cannot lead to an increase, but
you're comfortable with a negative decrease? Honestly, you make some good
points and the expression "by a factor of" has certainly been abused. I am
still bound by my prescriptivist approach to technical language, though. I
think using your approach, or the approach you are advocating, takes much of
the usefulness and clarity out of the terms.
Mike G.
lightbulb
The only thing I find unclear about your point is the switching from
division to multiplication for fractions. That is inconsistent. If, as
you say, 3 and 1/3 are implicitly the same, why use them both in this
context? Most people hate working with fractions, and if they could use 3
instead of 1/3, most would. The only reason to use a fraction in this
expression is to keep the language consistent. I'm sure that if you wanted
to use them the way you describe, you could. I would insist on a disclaimer
or having that information included in the directions as it is not very
"plain English", IMO.
Mike G.
rban...@shaw.ca
<cyber...@19-16-25-13-01-03.com> wrote:
>rbaniste wrote on 28 Feb 2005:
>
>> On 28 Feb 2005 00:40:27 GMT, CyberCypher wrote:
>[...]
>>>> Blessed are the simple of mind for they shall battle in aue and
>>>> struggle with words.
>>>
>>>Please explain yourself.
>>
>> I think it was a German who remarked that against stupidity even
>> the gods folded their tents, or something like that. When the
>> stupid themselves fold their tents and tootle off somewhere else
>> it is not only the gods who are relieved.
>
>You have only obfuscated your point by elaborating. Who are you calling
>stupid and why?
When you find your editorial hat again you might try asking this
rbaniste chap. I think he may give you the same answer I would. What
do you think, cypher my boy?
Paul Wolff
<ligh...@chartermi.net> writes
>
[...]
>
>We're going to have to agree to disagree on this one. I've stated my view
>in full on it several times in this thread. You're focusing on "decrease"
>and I'm focusing on "decrease by a factor of.'' Its evident that we have
>different priorities when interpreting math problems.
>
[...]
>
>In your view "decrease by a factor of" cannot lead to an increase,
That would be the default interpretation, overridden if the factor is
negative, or there is other context that clearly points to an increase
being the outcome.
>but
>you're comfortable with a negative decrease?
Yes, in a scientific or mathematical context - like a table of
decreases, with an occasional negative value.
>Honestly, you make some good
>points and the expression "by a factor of" has certainly been abused. I am
>still bound by my prescriptivist approach to technical language, though. I
>think using your approach, or the approach you are advocating, takes much of
>the usefulness and clarity out of the terms.
I am happy to acknowledge that.
lightbulb
<rban...@shaw.ca> wrote in message
news:qjb6211c89lu4bqlb...@4ax.com...
DID you write that or DID he?
Mike
John O'Flaherty
They didn't present a separate question, per se: the problem was framed
that way. Maybe they were trying to duplicate real-life bad usage.
I've figured out by now they definitely meant to go from 8 to 4.
--
john
John O'Flaherty
> John O'Flaherty <quia...@yahoo.com> wrote:
>
>>Murray Arnow wrote:
>>
>>>What is the book's name and who is the author?
>>
>>Physics for Scientists and Engineers, 5th edition.
>>Raymond A. Serway & Robert J. Beichner
>>The problem is #25 in the problems for chapter 26, Capacitance and
>>Dielectrics.
>>
>
>
> Serway has become popular in many schools for beginning physics. I think
> it derives from beautiful illustrations rather than excellent prose. His
> books are quite good but haven't been vetted like the old standbys like
> "Resnick and Halliday" or "Sears and Zemansky."
>
> You can do the authors a service by sending them or their publisher a
> comment on this bad wording. They should be grateful to hear such
> feedback.
>
>
>>>Badly worded problems are an unending source of trouble on examinations.
>>>What you think is understandable to everyone will be misunderstood by
>>>someone.
>>
>>Really. A lab practical exam: Find the third lowest frequency of
>>vibration of the string (n=3).
>>If it said third _from_ lowest, then it would shift it up one, I think.
>>And they didn't supply a formula or define n, which could be
>>wavelengths, half-wavelengths, nodes, or antinodes. I finally guessed
>>they meant 3 antinodes or half-waves.
>>
>
>
> Yes, that is bad wording. Incidentally, I don't agree with your
> conclusion, but that's the problem with poorly worded questions.
I'd be interested to know how you would interpret it.
--
john
CyberCypher
[...]
> to hold the position that "to decrease by" actually must mean to
> decrease. No matter what words and numbers follow it ("factor,"
> fractions, whole numbers) the actual amount in question must
> decrease. The phrase following the word decrease tells you how
> *much* it decreased by.
I have no idea how it should be written. I'll wait till Mike Hardy,
formerly of the UCLA Math Dept, or any other math professional, weighs
in on this.
> The main problem is that it appears that some people write the
> factor as a whole number, and some people write the factor as its
> reciprocal (a fraction), but in this case, they mean the same.
> Dividing by a whole number is the same as multiplying by its
> reciprocal. So if it says "decreased by a factor of 3" you divide
> by three (which is multiplying by one-third), and if it says
> "decreased by a factor of l/3" you multiply by one-third.
I agree with your comments here, Donna, and I agreed with your first
post in this thread. I'm just not qualified to comment on the math
idiom, but I am qualified to say how this is probably going to be
interpreted by someone with no knowledge of how math people write and
speak, viz. me.
You seem to be saying either that this is a disputed math usage or that
there is a choice of ways of saying it. I happy to see that math people
don't always agree.
CyberCypher
> <rban...@shaw.ca> wrote
>> On 28 Feb 2005 11:10:00 GMT, CyberCypher wrote:
>> >rbaniste wrote on 28 Feb 2005:
>> >> On 28 Feb 2005 00:40:27 GMT, CyberCypher wrote:
>> >[...]
>> >>>> Blessed are the simple of mind for they shall battle in aue
>> >>>> and struggle with words.
>> >>>
>> >>>Please explain yourself.
>> >>
>> >> I think it was a German who remarked that against stupidity
>> >> even the gods folded their tents, or something like that. When
>> >> the stupid themselves fold their tents and tootle off
>> >> somewhere else it is not only the gods who are relieved.
>> >
>> >You have only obfuscated your point by elaborating. Who are you
>> >calling stupid and why?
>>
>> When you find your editorial hat again you might try asking this
>> rbaniste chap. I think he may give you the same answer I would.
>> What do you think, cypher my boy?
>
> DID you write that or DID he?
He's just playing stupid games, Mike.
K. Edgcombe
CyberCypher <cyber...@19-16-25-13-01-03.com> wrote:
>
>I have no idea how it should be written. I'll wait till Mike Hardy,
>formerly of the UCLA Math Dept, or any other math professional, weighs
>in on this.
>
>there is a choice of ways of saying it. I happy to see that math people
>don't always agree.
All right, I'm a mathematician of a kind.
The wording is clearly unsatisfactory because it is not conveying what is
required unambiguously (some people *think* it is, but the OP was confused and
others differ).
Both proposed sets of rules for interpretation are also unsatisfactory:
(a) It is possible to be purist about it, which would
allow for "increase by a factor of 0.5" meaning "halve", and "decrease by a
factor of 0.5" meaning "double". Even within mathematics, it is better not to
be as perverse as this about the meanings of common words if it can be avoided.
I would read such things correctly, but I don't think it's fair to expect
physicists to.....
(b) Or it is possible to take the words "increase" or "decrease" as defining
whether the "factor" is to be a multiplicand or a divisor; this is all right
until you want to talk about changing by a factor of x where you don't know
how big x is. Since mathematicians always want to talk about x, roughly
speaking, this is also unsatisfactory.
The trouble is that the original wording contains too much information about
which way the change is going, leading to potential internal conflict
or to a perverse way of reading ordinary words. The solution is to give the
information (about which way the change is going) only once, and make sure that
once is unambiguous. The word "factor" has built-in ambiguity (in this
context; it's all right in many others) because we don't know which side of the
equation it goes.
So: multiplied by 0.5
divided by 2
halved
Katy
Katy
will all do.
CyberCypher
Thank you for that explanation, Katy. I hope we can lay this topic to
rest now.
John Dawkins
> Donna Richoux wrote on 28 Feb 2005:
> [...]
> > Except that Mike G. is in the minority here, and most of us appear
> > to hold the position that "to decrease by" actually must mean to
> > decrease. No matter what words and numbers follow it ("factor,"
> > fractions, whole numbers) the actual amount in question must
> > decrease. The phrase following the word decrease tells you how
> > *much* it decreased by.
>
> I have no idea how it should be written. I'll wait till Mike Hardy,
> formerly of the UCLA Math Dept, or any other math professional, weighs
> in on this.
As opposed to writers of physics textbooks, most mathematicians wouldn't
be caught dead using such language. Rather than " decreases by a factor
of 0.5" a mathematician would write "cut in half" or "halved".
Now if the factor 0.5 were changed to 0.347.....
--
J.
Areff
> I have no idea how it should be written. I'll wait till Mike Hardy,
> formerly of the UCLA Math Dept, or any other math professional, weighs
> in on this.
Are you thinking of Mike Oliver? Not that Mike Hardy isn't a math
professional too.
--
Steny '08!
don groves
It's the difference between everyday language and rigorous,
scientific or mathematical language. It's not *wrong* to say
"decrease by a factor of" to mean "divide by" in everyday
conversation, but in a science textbook, I would expect more
rigor.
--
dg (domain=ccwebster)
lightbulb
> lightbulb wrote on 28 Feb 2005:
> > <rban...@shaw.ca> wrote
> >> On 28 Feb 2005 11:10:00 GMT, CyberCypher wrote:
> >> >rbaniste wrote on 28 Feb 2005:
> >> >> On 28 Feb 2005 00:40:27 GMT, CyberCypher wrote:
> >> >[...]
> >> >>>> Blessed are the simple of mind for they shall battle in aue
> >> >>>> and struggle with words.
> >> >>>
> >> >>>Please explain yourself.
> >> >>
> >> >> I think it was a German who remarked that against stupidity
> >> >> even the gods folded their tents, or something like that. When
> >> >> the stupid themselves fold their tents and tootle off
> >> >> somewhere else it is not only the gods who are relieved.
> >> >
> >> >You have only obfuscated your point by elaborating. Who are you
> >> >calling stupid and why?
> >>
> >> When you find your editorial hat again you might try asking this
> >> rbaniste chap. I think he may give you the same answer I would.
> >> What do you think, cypher my boy?
> >
> > DID you write that or DID he?
>
> He's just playing stupid games, Mike.
>
So was I. DID is an appropriate acronym in reference to his post. Or else
it can be spoken as an initialism.
Mike G.
lightbulb
Maybe they'll add this topic to the AUE FAQ under the "circular debate"
department.
Mike G.
Donna Richoux
> "Donna Richoux" <tr...@euronet.nl> wrote in message
> > Except that Mike G. is in the minority here, and most of us appear to
> > hold the position that "to decrease by" actually must mean to decrease.
> > No matter what words and numbers follow it ("factor," fractions, whole
> > numbers) the actual amount in question must decrease. The phrase
> > following the word decrease tells you how *much* it decreased by.
> >
> > The main problem is that it appears that some people write the factor as
> > a whole number, and some people write the factor as its reciprocal (a
> > fraction), but in this case, they mean the same.
>
> > Dividing by a whole
> > number is the same as multiplying by its reciprocal. So if it says
> > "decreased by a factor of 3" you divide by three (which is multiplying
> > by one-third), and if it says "decreased by a factor of l/3" you
> > multiply by one-third.
> >
>
> The only thing I find unclear about your point is the switching from
> division to multiplication for fractions. That is inconsistent. If, as
> you say, 3 and 1/3 are implicitly the same, why use them both in this
> context? Most people hate working with fractions, and if they could use 3
> instead of 1/3, most would. The only reason to use a fraction in this
> expression is to keep the language consistent. I'm sure that if you wanted
> to use them the way you describe, you could. I would insist on a disclaimer
> or having that information included in the directions as it is not very
> "plain English", IMO.
>
In this discussion, we haven't found enough evidence to plot whether
this varies by region or by profession or what. I suspect that an
individual user, in normal circumstances, would only see *one* of those
two possibilities (either divide by 3 or multiply by l/3).
Just like if you drive on the right in your country, you can go miles
and miles and miles and never enounter the problem of driving on the
left. It's only when world travel is involved that that there's a
conflict.
Paul Wolff
<ligh...@chartermi.net> writes
>Maybe they'll add this topic to the AUE FAQ under the "circular debate"
>department.
Good idea. Let's start again. Your move...
lightbulb
> In message <UiLUd.7623$b42....@fe07.lga>, lightbulb
> <ligh...@chartermi.net> writes
> >Maybe they'll add this topic to the AUE FAQ under the "circular debate"
> >department.
>
> Good idea. Let's start again. Your move...
Shouldn't we wait just long enough for this thread to quit showing up on
newsreaders?
Mike G.
rban...@shaw.ca
<cyber...@19-16-25-13-01-03.com> wrote:
You betcha; harder than shelf-stocking is it not?
rban...@shaw.ca
That German chap knew what he was talking about, wot?
Paul Wolff
<ligh...@chartermi.net> writes
Peter Moylan
In fact, a change to 0.347 clarifies the issue. A mathematician or
theoretical physicist [*] would say "multiplied by a factor of 0.347"
or "scaled by a factor of 0.347". The words "increase" and "decrease"
don't even belong in the same sentence. If the original text had
avoided using those words there wouldn't have been a problem.
[*] An experimental physicist, on the other hand, .... I'm told
that there's a lot of rivalry between the experimental and
theoretical physicists. The theorists apparently think that the
experimentalists don't use big words like "multiply" and "divide".
According to the experimentalists, "a theoretical physicist is
someone whose existence is postulated to make the numbers balance,
but who is never observed in the laboratory".
--
Peter Moylan peter at ee dot newcastle dot edu dot au
http://eepjm.newcastle.edu.au (OS/2 and eCS information and software)
lightbulb
<rban...@shaw.ca> wrote in message
news:ht4721lopjg97t25m...@4ax.com...
http://cgd.best.vwh.net/home/quotes.htm
Against stupidity the very gods
Themselves contend in vain.
Johann Christoph Friedrich von Schiller
http://www.studiocleo.com/librarie/schiller/biography.html
Its the Ode to Joy guy. Hooda thunk it?
Mike G.
CyberCypher
Yes, I'm thinking of Mike "Oliver Hardy" Oliver of Laurel Canyon, LA.
John_Kane
CyberCypher wrote:
> John_Kane wrote on 28 Feb 2005:
> [...]
> > Slightly off topic, I have found that an almost essential tool for
> > reading non-ficiton is a calculator. Mind you, it helps in fiction
> > too some times. A month or so ago I read about the aftermath of an
> > ice storm on Canada's west coast: A city had begun to supply road
> > salt to citizens if they came and picked it up themselves. As I
> > recall the article in a newspaper about 4,000 people came and
> > picked up roughly 5000 tonnes of salt. I suspect that the
> > reporter or the editor mangled the material just a bit.
> >
> > Joel Best in his book Damned Lies and Statistics: Untangling
> > Numbers from the Media, Politicians, and Activists, University of
> > California Press (2001) gives a great example of the use of
> > numbers in a very poor way.
>
> Forty-five years ago I asked my boss to change my wages at the
> supermarket from whatever it was to $0.01/day and then double it
> every day. I knew then that I could have retired six weeks a
> millionaire (when being a millionaire meant something in the USA).
> >
> > As he says in describing "The Worst Social Statistic Ever"
> > --------------------------
> > 'The dissertation prospectus began by quoting a statistic--a
> > "grabber" meant to capture the reader's attention.
> > .......
> > So the prospectus began with this (carefully footnoted) quotation:
> > "Every year since 1950, the number of American children gunned
> > down has doubled." I had been invited to serve on the Student's
> > dissertation committee. When I read the quotation, I assumed the
> > Student had made an error in copying it. I went to the library and
> > looked up the article the Student had cited. There, in the
> > journal's 1995 volume, was exactly the same sentence: "Every year
> > since 1950, the number of American children gunned down has
> > doubled."
> >
> > This quotation is my nomination for a dubious distinction: I think
> > it may be the worst--that is, the most inaccurate--social
> > statistic ever." -----------------------------
> >
> > Why this is so bad is left as an exercise for the reader (or see
> > http://www.ucpress.edu/books/pages/9358/9358.intro.html for the
> > explaination. It is however a horrible error and shows that the
> > student quoting this statistic had paid no attention to what it
> > actually was saying.
>
> Right. He ignored the English and didn't do the math, as did the
> source of the student's quotation, the original idiot:
>
> [quote]
> Where did the article's Author get this statistic? I wrote the
> Author, who responded that the statistic came from the Children's
> Defense Fund (the CDF is a well-known advocacy group for children).
> The CDF's The State of America's Children Yearbook--1994 does state:
> "The number of American children killed each year by guns has doubled
> since 1950."[1] Note the difference in the wording--the CDF claimed
> there were twice as many deaths in 1994 as in 1950; the article's
> Author reworded that claim and created a very different meaning.
> [/quote
>
> > Unfortuately innumeracy is probably even more widespread than
> > illiteracy and with the many of the same kind of consequences. If
> > we combine the two then we have really serious problems of
> > comprehension and interpretation.
>
> This is not an example of innumeracy but of illiteracy. To translate
> "X has doubled since 1950" into "Every year since 1950, X has
> doubled" demonstrates a lack of understanding of plain and simple
> and, to me at least, unambiguous English.
Good point, it clearly is bad English but I would still argue it seems
to show innumeracy at least on the part of the student since he/she did
not understand that what the Author was saying was immpossible. Of
course the student may have been illiterate too.
Jordan Abel
>
> "Jordan Abel" <jma...@purdue.edu> wrote in message
> news:slrnd25f5l...@localhost.localdomain...
>> On 2005-02-27, lightbulb <ligh...@chartermi.net> wrote:
>> >> > The question was worded as a math problem. If, in everyday
>> >> > conversation, somebody asked me that question, I would ask them
>> >> > which they meant, reduction by a factor of two or by a factor of
>> >> > 0.5.
>> >>
>> >> I wouldn't. I'd ask whether the speaker meant 4 mm, which is what I
>> >> think the wording means. But maybe you know a lot more about math
>> >> than I do. I'd be a bit annoyed that the speaker was jargonating
>> >> instead of speaking plain English.
>> >
>> > It is, in fact, plain English. As I noted, 0.5 and 2 are not the same
>> > number.
>>
>> But when using "decreased by a factor of N", the only interpretation
>> that doesn't lead to something increasing is that numbers are considered
>> equivalent their reciprocals
>
> Why are you concerned about something increasing? What if it did increase?
We were talking about the use of the non-mathematical term "increase
by a factor of", and you claimed it meant "multiply even if that results
in a decrease". i'm concerned about something increasing because we're
talking about what the word "increase" means - it requires something to
increase.
> What if that was the whole point? Perhaps something was decreasing, so that
> was the language being used, and then the factor by which it decreased was
> measured at 0.5, indicating an increase? Math does offer its share of
> bullshit, like imaginary numbers. But setting a number equal to its
> reciprocal?
For purposes of the use of non-mathematical language about "decreasing"?
sure it does [though, for "increase", you should add 1 to the number in
that particular case - period. even if the number is greater than one.
"increase by a factor of N" [or "by N percent"] means "set equal to
X+X*N where X is the original number".