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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