Randomized selection of stimuli across trials

[HalleZ]

Hello,

I am trying to program an experiment where I have three different
words presented on each trial. I would like ePrime to uniquely select,
without replacement across trials in a single session, the three words
that get combined into a single trial so that this triplet is unique
for each person. Currently, I have a separate text object in my
TrialProcedure for each word (Word1, Word 2, Word3) with each of these
text objects pulling from the same list ("Words") of all of my words
(so, on each text object it pulls the attribute [Word] from the
"Words" list). In my list object called "Words" where all of my
stimuli are listed, I have the properties set so that the selection
method is "random" (i.e., without replacement). However, ePrime pulls
the same words within a trial (so, people might see "cat", "dog",
"cat" but what I want them to see is three unique words like "cat",
"dog", "bunny"). What did I do wrong? Is this property of no
replacement only applied across trials?

Thanks for the help!

-Halle

[Paul Groot]

Hi Halle,

You probably would like to use a separate Word list and include it as
nested list in your TrialList. Then add 3 separate attributes in the
trial list (Word1, Word2, Word3). The values of these attributes are
resp. [Word:0], [Word:1], [Word:2] (all trials the same). These will
pull 3 random words from the nested Word list and copy the values to
the attributes: Word1, Word2, Word3. Then use these 3 attributes in
your display objects as usual (i.e. resp [Word1], [Word2], [Word3]).
That should do it...

The attached EPrime 1.2 example demonstrates this mechanism. (You can
also import this script in EPrime 2)

Best,
Paul

2011/8/4 HalleZ <zha...@gmail.com>:

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[HalleZ]

Hi Paul,

Thanks so much for the example script--that was extremely helpful! I
think perhaps when I initially posted the question I oversimplified my
problem a bit. So, let me see if I can more fully explain what I want
to program.

On each trial, I want to select a unique triplet that does not repeat
across trials (e.g., WordA, WordB, WordC). However, what I'm really
selecting is the parent word list from which the stimuli are pulled
(e.g., selecting WordA means that wordA1, wordA2, wordA3, and wordA4
are what get presented to the subject so that an entire trial looks
like wordA1, wordA2, wordA3, wordA4, wordB1, wordB2, wordB3, wordB4,
wordC1, wordC2, wordC3, wordC4).

Following the way you suggested using the nesting of word lists, I
believe I have it so that the words do not repeat across trials.
However, it seems to be pulling the same word multiple times within a
single trial (e.g., wordA1, wordA2, wordA3, wordA4, wordB1, wordB2,
wordB3, wordB4, wordA1, wordA2, wordA3, wordA4). I'm assuming there's
just another level of nesting that I'm missing here, but I can't seem
to figure out where/how to nest this!

thanks,
Halle

On Aug 8, 4:13 am, Paul Groot <pfc.gr...@gmail.com> wrote:
> Hi Halle,
>
> You probably would like to use a separate Word list and include it as
> nested list in your TrialList. Then add 3 separate attributes in the
> trial list (Word1, Word2, Word3). The values of these attributes are
> resp. [Word:0], [Word:1], [Word:2] (all trials the same). These will
> pull 3 random words from the nested Word list and copy the values to
> the attributes: Word1, Word2, Word3. Then use these 3 attributes in
> your display objects as usual (i.e. resp [Word1], [Word2], [Word3]).
> That should do it...
>
> The attached EPrime 1.2 example demonstrates this mechanism. (You can
> also import this script in EPrime 2)
>
> Best,
> Paul
>

> 2011/8/4 HalleZ <zhal...@gmail.com>:

>
> > Hello,
>
> > I am trying to program an experiment where I have three different
> > words presented on each trial. I would like ePrime to uniquely select,
> > without replacement across trials in a single session, the three words
> > that get combined into a single trial so that this triplet is unique
> > for each person. Currently, I have a separate text object in my
> > TrialProcedure for each word (Word1, Word 2, Word3) with each of these
> > text objects pulling from the same list ("Words") of all of my words
> > (so, on each text object it pulls the attribute [Word] from the
> > "Words" list). In my list object called "Words" where all of my
> > stimuli are listed, I have the properties set so that the selection
> > method is "random" (i.e., without replacement). However, ePrime pulls
> > the same words within a trial (so, people might see "cat", "dog",
> > "cat" but what I want them to see is three unique words like "cat",
> > "dog", "bunny"). What did I do wrong? Is this property of no
> > replacement only applied across trials?
>
> > Thanks for the help!
>
> > -Halle
>
> > --
> > You received this message because you are subscribed to the Google Groups "E-Prime" group.
> > To post to this group, send email to e-p...@googlegroups.com.
> > To unsubscribe from this group, send email to e-prime+u...@googlegroups.com.
> > For more options, visit this group athttp://groups.google.com/group/e-prime?hl=en.
>
>
>

>  MultipleValuesFromNestedList.es
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