It appears that both VO-Event and DAL have similar requirements for a
standard nomenclature for object classification, e.g.,
process.variation.burst;em.gamma
process.variation.burst;em.X-ray
and so forth as has been suggested. We had a similar discussion in DAL a while back but I will summarize the conclusions again here.
In DAL (and probably VO-Event as well) this comes up in two different areas, object description via query response metadata, and in the query itself.
For object description in the query response one wants as precise a description of the object classification as is known. Long descriptive UCD-like descriptions as in the examples above are fine.
For a query it is important that a more coarse-grained classification be possible, which allows a single string to potentially match many fine-grained type classifiers. For example, "star" could match many object types. It would be good if these coarse-grained classifier names could be brief for use in a query, as they will probably pass through to the service unchanged, originating from a human user or client application. The relationships between the coarse-grained names and the detailed classifications could be one-to-many and possibly hierarchical as well.
It would be good to avoid the use of special metacharacters in these names. For example, in our earlier discussions, "*" was used as a shorthand for "star" in the naming convention proposed, but this could cause problems for software, for example if pattern-matching is used.
We will need to standardize both detailed object classification and query input, so it is important to address both of these areas in whatever scheme we come up with. One way to ensure that this happens might be to implement an "object resolver" service or web page to map short names to lists of classifiers once a list of detailed classifications becomes available. - Doug Received on 2006-05-27Z00:02:15