[Crm-sig] Issue 326 Resolving inconsistencies between E2, E4, E52 and E92

Martin Doerr martin at ics.forth.gr
Tue Mar 12 22:55:04 EET 2019


Dear Robert,

I agree that this is a "non-intended" model, as Guarino describes it. He 
also points out, that no ontology can exclude all unintended models.

However, I do not see actually why this kind of model would be 
disallowed with a link. If I am not mistaken, anything that can be said 
with the IsA can be said with the 1-1 link. Just add the links, isn't it?

Indeed, parts can have a smaller time of existence than the whole. This 
is intended. To declare a whole which has no portion surviving from 
beginning to end of the whole is also realistic. To declare a whole as 
E22 which has no properties poses a question about its identity.

So, I regard the example as a bad application, not a shortcoming of the 
schema, and a question of elaborating the identity conditions for 
physical objects.

Opinions?

Martin



On 3/12/2019 4:27 PM, Robert Sanderson wrote:
>
> Dear Martin, all,
>
> I agree with your assessment into the four categories, and that the 
> first three are met, and the last is more complicated.
>
> I also agree with the formalism for E4. It moves some of the 
> complexity around, and doesn’t introduce inconsistency for the 
> temporal side of things for subclasses of E2.
>
> However, I agree with George that this does not hold true for the 
> other sub class of E92, being E18 Physical Thing.  With this subclass 
> assertion, we can partition physical things based on time and then 
> make assertions about those partitions using all of the sub-classes of 
> E18.  For example, to say that the Nightwatch had a width of 17 feet 
> between its production in 1642 and 1715 when it was trimmed to fit on 
> a wall in the Amsterdam town hall, we could have an E22 for the 
> painting throughout time, and use P10 to reference further E22s, each 
> of which were clarified with P160 as to their temporal projection. 
> These projections could then have different dimensions.
>
> <Nightwatch> a E22_Man-Made_Object ;
>
>     P10i_contains <Large_Nightwatch> , <Small_Nightwatch> .
>
> <Large_Nightwatch> a E22_Man-Made_Object ;
>
>     P160_has_temporal_projection [
>
>          a E52_Time-Span ;
>
>          P81a_begin_of_the_begin “1642-01-01”
>
>          P82a_end_of_the_end “1715-12-31”  ] ;
>
>      P43_has_dimension [
>
>         P2_as_type <width-type> ;
>
>         P90_has_value 17 ;
>
>         P91_has_unit <feet-unit> ]
>
> (and the same for Small_Nightwatch, starting 1715 with 14.3 feet as width)
>
> This seems antithetical to the intent of the model (as I understand 
> it) where activities (such as Modification in this case) are kept 
> separate from the entities that they affect.
>
> This particular pattern could be prevented by having E92 not be a sub 
> class of E18, without affecting the P160 / P4 discussion.  However, I 
> note some issues with making only this split:
>
> ·It would still be valuable to have the STV of a physical thing, in 
> order to calculate the intersection between the STV that a physical 
> object projects with Periods (that are themselves STVs). So it would 
> be valuable to introduce a relationship between E18 and E92, 
> introducing pattern inconsistency.
>
> ·While Period and Event seem to share the identity conditions with 
> STV, Activity and below start to seem less identical. I worry that I 
> become the space-time volume of the sum of my activities… and then I 
> am a STV again, even though we removed it from E18 for just this reason.
>
> ·The same issue for P160 / P4 would apply for P161 / P53 – the spatial 
> projection of the object is its former or current location, as they 
> have the same identity currently.
>
> So overall, I think my position is that for consistency of the model, 
> E92 should not be a subclass of either E4 or E18, but instead related 
> via a property.
>
> Hope that helps!
>
> Rob
>

-- 
------------------------------------
  Dr. Martin Doerr
               
  Honorary Head of the
  Center for Cultural Informatics
  
  Information Systems Laboratory
  Institute of Computer Science
  Foundation for Research and Technology - Hellas (FORTH)
                   
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  GR70013 Heraklion,Crete,Greece
  
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  Email: martin at ics.forth.gr
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