[Antiquist] Fuzzy Dates
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macroy
May 7, 2010, 8:32:35 AM5/7/10
to Antiquist
Hi guys,
I've just joined the list following recent serendipitous discussions
with Antiquist member Andrew Larcombe.
I'm a database developer and amateur military historian and have been
working for some years on a solution to the problem of managing fuzzy
dates associated with WW2 personnel, events, documents and photos,
having failed to find any ready-made answers.
For what it's worth, I've now formalised my findings and thinking into
a White Paper called...
"Fuzzy dates in military history databases. FZY-D, a proposed
variation on the ISO 8601:2004(E) datetime format"
...and have uploaded it as a pdf: MGT-WP-01v1.2.pdf.
Although my particular area is military history, I believe that the
proposed format may be useful to a wide range of historical data
storage and manipulation situations, so I would be very interested to
get some feedback from Antiquist members.
Cheers,
Roy
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I've just joined the list following recent serendipitous discussions
with Antiquist member Andrew Larcombe.
I'm a database developer and amateur military historian and have been
working for some years on a solution to the problem of managing fuzzy
dates associated with WW2 personnel, events, documents and photos,
having failed to find any ready-made answers.
For what it's worth, I've now formalised my findings and thinking into
a White Paper called...
"Fuzzy dates in military history databases. FZY-D, a proposed
variation on the ISO 8601:2004(E) datetime format"
...and have uploaded it as a pdf: MGT-WP-01v1.2.pdf.
Although my particular area is military history, I believe that the
proposed format may be useful to a wide range of historical data
storage and manipulation situations, so I would be very interested to
get some feedback from Antiquist members.
Cheers,
Roy
--
You received this message because you are subscribed to the Google Groups "Antiquist" group.
To post to this group, send email to anti...@googlegroups.com.
To unsubscribe from this group, send email to antiquist+...@googlegroups.com.
For more options, visit this group at http://groups.google.com/group/antiquist?hl=en.
Jon
May 9, 2010, 9:01:36 AM5/9/10
to Antiquist
Hello.
My name is Jon Holmen. I have just become a member of this list and
this is a response to macroy
about the fuzzy date format proposal. I think this is an interesting
work, but I also believe that before one can agree on a standard for
representing fuzzy dates, one has to clarify the underlying model.
This is an attempt to clarify at least some important aspects about
dating based on CIDOC-CRM ( ISO 217727:2006, standard for
documentation of museum material). I have contributed to a paper about
these questions presented at CAA2009, Williamsburg. The paper is
available here: www.edd.uio.no/artiklar/arkeologi/holmen_ore_caa2009.pdf
Hera are some main aspects about dating seen from my point of view:
1.When you assign dates to something, you assign dates to one or a
collection of events or activities. F.i. if you assign dates an
object, you really assign dates to when it has been produced, used,
found or other; that is when, on the time line, one (or more) of these
events took place.
2.Any physical or mental event on this time line has duration. In
other words; our dates is intervals, not points. This is true even if
we often gives just one number for the representation. When resolution
is low enough this number covers both start and end of the given
interval. F.i. When you say «the treaty was signed at 08.05.1945», you
really say «it was signed at sometimes in between 00:00:00 08.05.1945
and 23:59:59 08.05.1945 (closed interval) and it took some time less
than a day» ( if you have chosen secs as your time resolution and we
do not consider time zones).
In CIDOC-CRM these dates are called timespans that is connected to
their respective events.
3.The fuzziness of the dating is reflected in the determination of the
start- and endpoints of these timespans. If we go back to the signing
of the treaty in pt.2, there are two questions.
The first is of course to define what we mean by signing the treaty:
Is it the whole ceremony, only the putting of signatures on the
document, or perhaps should some of the preparations also be included.
This is a question of what you are dating and should not be mixed up
with the actual model for the timespan, that has a clear cut
startpoint and a clear cut endpoint.
The second question is how to represent fuzziness in the measurement
of this (clear cut )start- and endpoint of the timespan.
Let us just say that in our example we are dating the putting of
signatures on the document.
Fortunately we have a photo (with a timestamp that we trust ) of the
signing, taken 12:15, 08.05.1945. And we have additional information
about the ceremony stating that it started 11:00 and ended 13:00.
In this case we would say that the signing took place at sometimes in
between 11:00:00 and 13:00:00, 08.05.1945. In CIDOC-CRM the relation
between the interval formed by these to dates and the timespan is
called «occurred within».
We also know that around 12:15 they were writing their names on the
document, so the start of writing their names had to be before, and
the end had to be after picture was taken. But since the resolution of
this dating is minutes, we can only determine the start to be before
12:15:59 and the end to be after 12:15:00. This gives us two
intervals, one for the occurrence of the start of the event (between
11:00:00 and 12:15:59) , and one for the occurrence of the end of the
event (between 12:15:00 and 13:00:00). As you can see, the dating of
the event with fuzziness needs 4 numbers (+ probably resolution,time
zone a.s.o.):
Earliest possible start, latest possible start, earliest possible end
and latest possible end.
In this example (so far) latest possible start is after earliest
possible end, leaving no sure point where the event actually took
place.
Luckily for us another photo shows up, still showing signing of the
same documents. This photo has timestamp 12:20. Adding this
information moves the earliest possible end to 12:20:00. So we have a
positive time gap between latest possible start (12:15:59) and
earliest possible end (12:20:00), and therefor an interval where the
signing was surely ongoing.
In CIDOC-CRM the relation between the interval formed by these two
dates and the timespan is called «ongoing throughout».
4.By using this conceptual «format» for dating, all kind of date
arithmetic in terms of relations between timespans, like occurred
before, overlaps a.s.o. (the so called Allen operators) is easily
extended from intervals with exact start and end to intervals with
fuzzy start and end. (See the paper).
I hope that this will clarify some of the aspects with fuzzy dates and
perhaps give more input to possible implementations of formats and
algorithms to work with these questions.
Best regards, Jon
My name is Jon Holmen. I have just become a member of this list and
this is a response to macroy
about the fuzzy date format proposal. I think this is an interesting
work, but I also believe that before one can agree on a standard for
representing fuzzy dates, one has to clarify the underlying model.
This is an attempt to clarify at least some important aspects about
dating based on CIDOC-CRM ( ISO 217727:2006, standard for
documentation of museum material). I have contributed to a paper about
these questions presented at CAA2009, Williamsburg. The paper is
available here: www.edd.uio.no/artiklar/arkeologi/holmen_ore_caa2009.pdf
Hera are some main aspects about dating seen from my point of view:
1.When you assign dates to something, you assign dates to one or a
collection of events or activities. F.i. if you assign dates an
object, you really assign dates to when it has been produced, used,
found or other; that is when, on the time line, one (or more) of these
events took place.
2.Any physical or mental event on this time line has duration. In
other words; our dates is intervals, not points. This is true even if
we often gives just one number for the representation. When resolution
is low enough this number covers both start and end of the given
interval. F.i. When you say «the treaty was signed at 08.05.1945», you
really say «it was signed at sometimes in between 00:00:00 08.05.1945
and 23:59:59 08.05.1945 (closed interval) and it took some time less
than a day» ( if you have chosen secs as your time resolution and we
do not consider time zones).
In CIDOC-CRM these dates are called timespans that is connected to
their respective events.
3.The fuzziness of the dating is reflected in the determination of the
start- and endpoints of these timespans. If we go back to the signing
of the treaty in pt.2, there are two questions.
The first is of course to define what we mean by signing the treaty:
Is it the whole ceremony, only the putting of signatures on the
document, or perhaps should some of the preparations also be included.
This is a question of what you are dating and should not be mixed up
with the actual model for the timespan, that has a clear cut
startpoint and a clear cut endpoint.
The second question is how to represent fuzziness in the measurement
of this (clear cut )start- and endpoint of the timespan.
Let us just say that in our example we are dating the putting of
signatures on the document.
Fortunately we have a photo (with a timestamp that we trust ) of the
signing, taken 12:15, 08.05.1945. And we have additional information
about the ceremony stating that it started 11:00 and ended 13:00.
In this case we would say that the signing took place at sometimes in
between 11:00:00 and 13:00:00, 08.05.1945. In CIDOC-CRM the relation
between the interval formed by these to dates and the timespan is
called «occurred within».
We also know that around 12:15 they were writing their names on the
document, so the start of writing their names had to be before, and
the end had to be after picture was taken. But since the resolution of
this dating is minutes, we can only determine the start to be before
12:15:59 and the end to be after 12:15:00. This gives us two
intervals, one for the occurrence of the start of the event (between
11:00:00 and 12:15:59) , and one for the occurrence of the end of the
event (between 12:15:00 and 13:00:00). As you can see, the dating of
the event with fuzziness needs 4 numbers (+ probably resolution,time
zone a.s.o.):
Earliest possible start, latest possible start, earliest possible end
and latest possible end.
In this example (so far) latest possible start is after earliest
possible end, leaving no sure point where the event actually took
place.
Luckily for us another photo shows up, still showing signing of the
same documents. This photo has timestamp 12:20. Adding this
information moves the earliest possible end to 12:20:00. So we have a
positive time gap between latest possible start (12:15:59) and
earliest possible end (12:20:00), and therefor an interval where the
signing was surely ongoing.
In CIDOC-CRM the relation between the interval formed by these two
dates and the timespan is called «ongoing throughout».
4.By using this conceptual «format» for dating, all kind of date
arithmetic in terms of relations between timespans, like occurred
before, overlaps a.s.o. (the so called Allen operators) is easily
extended from intervals with exact start and end to intervals with
fuzzy start and end. (See the paper).
I hope that this will clarify some of the aspects with fuzzy dates and
perhaps give more input to possible implementations of formats and
algorithms to work with these questions.
Best regards, Jon
Paul Cripps
May 10, 2010, 5:33:34 AM5/10/10
to anti...@googlegroups.com
Morning all,
I would like to second Jon. In the EH ontological modelling work, based
on CIDOC-CRM and now forming part of the Star project, temporal
reasoning in archaeology can be summarised as two sets of events, linked
by Places and Stuff; the first set represents things that happened in
the past relating to particular places and material including deposits
and objects (eg deposition, context formation, the production of an
object, the deposition of same object, etc) and the second set
represents the activities of archaeologists working with and
interpreting the first set (excavation, drawings plans/sections, finding
an object, inferring timespans relating to the various Events in the
past).
Such a model, based entirely on events with associated timespans allows
us to record what happened in the past in the way in which Jon describes
but also then to qualify assertions made in the present (ie who said
what about what, when and based on what evidence). Thus we can eg have
multiple phasing/chronological/temporal inferences about archaeological
sites in addition to having fuzziness regarding the actual events in the
past. Another layer of (explicit) fuzziness if you will!
This was presented at CAA 2004 in Prato and I believe the proceedings
are still in press...?
Keith May and Doug Tudhope may also have more to add here from a Star
perspective. And the CAA Semantic SIG group may be a good place for
discussion in more detail on using CIDOC-CRM for this kind of thing.
Cheers,
Paul.
I would like to second Jon. In the EH ontological modelling work, based
on CIDOC-CRM and now forming part of the Star project, temporal
reasoning in archaeology can be summarised as two sets of events, linked
by Places and Stuff; the first set represents things that happened in
the past relating to particular places and material including deposits
and objects (eg deposition, context formation, the production of an
object, the deposition of same object, etc) and the second set
represents the activities of archaeologists working with and
interpreting the first set (excavation, drawings plans/sections, finding
an object, inferring timespans relating to the various Events in the
past).
Such a model, based entirely on events with associated timespans allows
us to record what happened in the past in the way in which Jon describes
but also then to qualify assertions made in the present (ie who said
what about what, when and based on what evidence). Thus we can eg have
multiple phasing/chronological/temporal inferences about archaeological
sites in addition to having fuzziness regarding the actual events in the
past. Another layer of (explicit) fuzziness if you will!
This was presented at CAA 2004 in Prato and I believe the proceedings
are still in press...?
Keith May and Doug Tudhope may also have more to add here from a Star
perspective. And the CAA Semantic SIG group may be a good place for
discussion in more detail on using CIDOC-CRM for this kind of thing.
Cheers,
Paul.
MAY, Keith
May 10, 2010, 7:18:39 AM5/10/10
to anti...@googlegroups.com
Dear all,
Agree with Jon. Key thing is to model Events and use Timespans.
'Fuzziness' is a derivative of not knowing the 'exact' (however you try
to measure it) start and end point of an event/timespan.
If you start to consider Events philosophically you seem to find all
events are measured imprecisely, but to increasing levels of accuracy,
depending upon the units of measurement used (e.g. the nearest year,
day, second, millisecond? and so on into the realm of quantum physics).
Agree with Paul. Using Events and Timespans allows you to apply a range
of relations both to, and between, other events, timespans, people and
things.
I would recommend looking at J F Allen's temporal operators for
modelling some key relationships between Fuzzy Timespans:
http://web.mit.edu/larsb/Public/16.412/pset%204/allen94actions.pdf
Best wishes...currently with limited time due to nursing sick child -
now that's really fuzzy time :-)
Keith
Agree with Jon. Key thing is to model Events and use Timespans.
'Fuzziness' is a derivative of not knowing the 'exact' (however you try
to measure it) start and end point of an event/timespan.
If you start to consider Events philosophically you seem to find all
events are measured imprecisely, but to increasing levels of accuracy,
depending upon the units of measurement used (e.g. the nearest year,
day, second, millisecond? and so on into the realm of quantum physics).
Agree with Paul. Using Events and Timespans allows you to apply a range
of relations both to, and between, other events, timespans, people and
things.
I would recommend looking at J F Allen's temporal operators for
modelling some key relationships between Fuzzy Timespans:
http://web.mit.edu/larsb/Public/16.412/pset%204/allen94actions.pdf
Best wishes...currently with limited time due to nursing sick child -
now that's really fuzzy time :-)
Keith
Anthony Beck
May 10, 2010, 8:15:35 AM5/10/10
to anti...@googlegroups.com
Sorry from phone. Brief and typos.
There's also a requirement to distinguish between data sources and absolute and relative dates.
For example an excavated context can derive dates from different sources including
C14
Relative strat and/or group
Pottery
The latter has a complex classification system exacerbated by periodic clumping and splitting and geographical bias.
Hence, I agree with all about understanding the model and particularly with Paul on multiple approaches to model dating. This should include persistent URIs so that data/interpretations can be re-evaluated when supporting pottery (or alternative) sequences change.
Ant
On 10 May 2010 12:15, "MAY, Keith" <Keit...@english-heritage.org.uk> wrote:
Dear all,
Agree with Jon. Key thing is to model Events and use Timespans.
'Fuzziness' is a derivative of not knowing the 'exact' (however you try
to measure it) start and end point of an event/timespan.
If you start to consider Events philosophically you seem to find all
events are measured imprecisely, but to increasing levels of accuracy,
depending upon the units of measurement used (e.g. the nearest year,
day, second, millisecond? and so on into the realm of quantum physics).
Agree with Paul. Using Events and Timespans allows you to apply a range
of relations both to, and between, other events, timespans, people and
things.
I would recommend looking at J F Allen's temporal operators for
modelling some key relationships between Fuzzy Timespans:
http://web.mit.edu/larsb/Public/16.412/pset%204/allen94actions.pdf
Best wishes...currently with limited time due to nursing sick child -
now that's really fuzzy time :-)
Keith
-----Original Message-----
From: anti...@googlegroups.com [mailto:anti...@googlegroups.com] O...
Behalf Of Paul Cripps
Sent: 10 May 2010 10:34
To: anti...@googlegroups.com
Subject: RE: [Antiquist...
Andrew Larcombe
May 21, 2010, 7:55:57 AM5/21/10
to anti...@googlegroups.com
Picking this up again, Sean Gillies tweeted a link to a doc which seems
relevant to this discussion:
http://twitter.com/sgillies/statuses/14421565880
Cheers,
A
relevant to this discussion:
http://twitter.com/sgillies/statuses/14421565880
Cheers,
A
Roy Paterson
May 24, 2010, 7:29:34 AM5/24/10
to Antiquist
Thanks for the responses, and for drawing my attention to J.F. Allen's
"Allen Operators", which add another useful layer to my thinking and
proposals.
Cheers,
Roy
"Allen Operators", which add another useful layer to my thinking and
proposals.
Cheers,
Roy
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