[Crm-sig] issue-288-AV_MD.doc

Richard Light richard at light.demon.co.uk
Thu Jan 11 18:06:36 EET 2018


On 11/01/2018 14:39, Martin Doerr wrote:
> Dear Richard,
>
> Your comments well-taken, but I regard it as pointless to use less
> precise data types. This is, to my opinion, exclusively an issue of
> automatic conversion
> in the data entry forms. We at FORTH have conversion libraries. Data
> entry utility ("ca 730 BC") must not be confused with internal data
> representation for interoperability (xsd:....), and not with
> ontological-logical modelling (time as isomorphic with real numbers).
>
> I do not know how RDF-compatible databases do arithmetic with mix of
> time data types. Any insight? We must avoid meaningless equality
> between imprecise dates. I assume there is no default interval
> arithmetic in place that could handle 28-6-1951 to be  possibly before
> something that happened in "1951" .
Martin,

So we agree that the ultimate storage format should be precise, in the
manner described by the draft document.  I take your point about the
distinction between a data entry interface and the ultimate storage
format in the RDF.  However, I think a description of our RDF solution
for P81/P82 which is expressed solely in these terms will convince most
practitioners that our RDF implementation is too complex to be used with
'real' museum data.

I think it would be a good idea to include some examples of dates, in a
form which might be found in collections catalogues, and show (a) how
they should be expressed in abstract terms (P81/P82) and then (b) how
they should be rendered as RDF (P81a/P81b/P82a/P82b).  We can also point
out that these conversions can be carried out programmatically.

Best wishes,

Richard

>
> I copy to Christian-Emil, because he should give us his theory of
> negative P81 intervals.
>
> Best,
>
> Martin
>
>
>
> On 1/11/2018 3:50 PM, Richard Light wrote:
>>
>> Hi,
>>
>> Not all of my corrections were picked up. Updated version (with some
>> other minor changes) attached. I tried desperately to switch on
>> 'track changes' (saving it as .docx in an attempt to do so), but I
>> have no idea whether Word has actually done this.  I did try!
>>
>> I wonder if it is helpful to include the paragraph about overlapping
>> 'end of begin' and 'begin of end': the concept is already hard enough
>> to understand without throwing this into the mix.
>>
>> As regards the substance of the proposal, I would observe that there
>> are other W3C date types, for example gDate and gYear [1].  I agree
>> with the goal of expressing dates in a way which is amenable to
>> machine processing, but the suggested approach appears to require
>> users to record to a spurious precision, which will never be present
>> in the source data. 
>>
> No, see above.
>>
>> (If we're following W3C guidelines in full, a DateTime value should
>> have an associated time zone, declared explicitly or implicitly
>> assumed to be UTC.  We don't actually give an example showing this.)
>>
> Yes, of course.
>>
>> I suggest, instead, that we say that when a W3C date, of whatever
>> sort, is given as the value of P81a or P82a, then it should be
>> interpreted as representing the /beginning /of the time period
>> expressed by that date.  When such a date is given as the value of
>> P81b or P82b, it should be interpreted as representing the /end /of
>> the time period expressed by that date.  (Re-reading the text, I do
>> wonder if this is what was actually meant.  It depends what you mean
>> by "the implementation". If so, I certainly misunderstood it the
>> first time around.)
>>
> Yes, that's what I meant, but at data entry time. We have an
> interpreter for the AAT guidelines how to record time, which has all
> those "ca" etc. There is also the "display date P79, P80, to capture
> the scholarly expression.
>>
>> I think the guidance should contain examples using both gYear and
>> gDate, showing how to record e.g. "date of birth recorded as
>> 4.12.1854" and "building not started before 1736; definitely
>> happening 1745-1750; finished by 1754 when it was opened" as RDF.
>>
>> Best wishes,
>>
>> Richard
>>
>> [1] https://www.w3.org/TR/xmlschema11-2/#gYear
>>
> Best,
>
> Martin
>>
>>
>> On 10/01/2018 19:38, Martin Doerr wrote:
>>>
>>> Here my latest edits, thanks to Richard's comments:-)
>>>
>>>
>>> -- 
>>> --------------------------------------------------------------
>>>  Dr. Martin Doerr              |  Vox:+30(2810)391625        |
>>>  Research Director             |  Fax:+30(2810)391638        |
>>>                                |  Email: martin at ics.forth.gr |
>>>                                                              |        
>>>                Center for Cultural Informatics               |
>>>                Information Systems Laboratory                |
>>>                 Institute of Computer Science                |
>>>    Foundation for Research and Technology - Hellas (FORTH)   |
>>>                                                              |
>>>                N.Plastira 100, Vassilika Vouton,             |
>>>                 GR70013 Heraklion,Crete,Greece               |
>>>                                                              |
>>>              Web-site: http://www.ics.forth.gr/isl           |
>>> --------------------------------------------------------------
>>
>> -- 
>> *Richard Light*
>
>
> -- 
> --------------------------------------------------------------
>  Dr. Martin Doerr              |  Vox:+30(2810)391625        |
>  Research Director             |  Fax:+30(2810)391638        |
>                                |  Email: martin at ics.forth.gr |
>                                                              |        
>                Center for Cultural Informatics               |
>                Information Systems Laboratory                |
>                 Institute of Computer Science                |
>    Foundation for Research and Technology - Hellas (FORTH)   |
>                                                              |
>                N.Plastira 100, Vassilika Vouton,             |
>                 GR70013 Heraklion,Crete,Greece               |
>                                                              |
>              Web-site: http://www.ics.forth.gr/isl           |
> --------------------------------------------------------------

-- 
*Richard Light*
-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://lists.ics.forth.gr/pipermail/crm-sig/attachments/20180111/1b561773/attachment.html>


More information about the Crm-sig mailing list