Dear all,
In the SIG meeting at CIDOC 2008 in Athens I was asked to write a draft
for a new scope note for E55 Type and adjust the paragraphs about types
in the introduction. Yuo will find my suggestion for the scope note
below. I postpone the intro part until a decision in taken on the scope
note.
The scope note is based on the original and on Guenther's suggestion
from May. The intention has been to make the scope not more explicit on
E55 Type's function as an interface to external classification systems
and to avoid the use of the term 'meta class'. In my opinion a type in
the CRM is a term, concept or predicate. It is not equal to the set
denoted by this term. Martin pointed out in an email that there is very
little difference between the interpretation of a CRM class and this
interpretation of a type, eg 'information carrier' (CRM class) and
'wineclass' type.
I agree that any CRM class (as a concept) and and instance of E55 have
the same extensional intentional set/term duality. A difference is that
we do not have any mechanisms inside CRM (if we do not follow the
suggestion from Vladimir Ivanov) to speak about a CRM class as a whole
as we can with respect to an instance of E55. So even though 'wineglass'
seen from a bird's view of the model is the same beast as 'information
carrier' (hypothetical sets of something), there is a difference in the
model qua a formal system.
Regards,
CHristian-Emil
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NEW TEXT E55 Scope Note
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E55
Type
Subclass of: E28 Conceptual Object
Superclass of: E56 Language
E57 Material
E58 Measurement Unit
Scope note:
The class E55 Type comprises concepts (universals) and hence provides an
interface to domain specific concepts external to the CRM. In this
fashion, a connection between the CRM and a particular (external) domain
concept as a subclass of E55 Type can be established.
This hierarchical relation allows for additional refinement through
sub-typing of the classes (of the CRM) which represent important
typological distinctions but where the given user group does not
consider it necessary to give a further analysis of the classes by
extending the CRM with new sub classes. The interpretation of these
sub-types is based on the agreement of the specific groups.
A type, that is, an instance of E55 Type can be interpreted in several
ways. It can be seen as a term in a thesaurus or as predicate with a
free variable in a logical system. The instances of the CRM classes
having a given type (e.g. through P2 has type) at a given point in time
form a set or a class. However, this class or set is not identical to
the type.
E55 Type reflects the characteristic use of terms like "Object Type",
"Category", "Classification" etc in museum documentation. Such fields
are used for terms that declare that the object belongs to a particular
category or class of items. It has however nothing to do with the term
`type' in Natural History (cf. E83 Type Creation) which is a E24
Physical Man-Made Thing (eg an dried insect on a needle) . But E55 Type
includes the notion of a `taxon' which are concepts.
Ideally, (external) subclasses of the class E55 Type should be organised
into thesauri, with scope notes, illustrations, etc. to clarify their
meaning. In general, it is expected that different domains and cultural
groups will develop different thesauri in parallel. Consistent
reasoning on the expansion of subterms used in a thesaurus is possible
insofar as it conforms to both the classes and the hierarchies of the
CRM. E56 Language, E57 Material and E58 Measurement Unit have been
defined explicitly as elements of the E55 Type hierarchy because they
are used categorically in the CRM without reference to instances of
them, i.e. the CRM does not foresee the description of instances of
instances of them, e.g., the property instance `P45 consists of : gold'
does not refer to a particular instance of gold.
