Difference: ResourceMetadataRFC (14 vs. 15)

Resource Metadata RFC

This document will act as RFC centre for the Resource Metadata V1.0 Proposed Recommendation.

Comments

Source is a Dublin Core element and refers to a single bibliographic reference. I don't think we should change it.

ReferenceURL is "A URL..."; I think resource providers should select the most relevant URL, if there are many, and give that here.

The coverage elements in 3.4 really need to derive from the STC definitions. They stand alone here because when this was first developed STC was not very far along. I will verify that these definitions are consistent, and that a reference to STC is provided.

As for making arrays out of the data quality metadata, my fear is that is going to lead to such complicated metadata structures that no one will be able to understand them. As the document notes, "The following metadata elements are intended to capture the most basic measures of data quality, and may well require extensions as VO usage practices evolve and become more sophisticated."

As for combining the spectral coverage metadata into an array of structures, this seems to me an implementation detail of the schema.

ObjectDensity is described as "typical". At the resource level I would really hesitate to try to express more than this.

Format is already described as a list. The details of the implementation are again left to the schema.

• Bandpass names : by GuyRixon : The list of approved names need to be stored somewhere and referenced from the current document. There are too many conflicting conventions for naming bandpasses to leave this loose. C.f. unit notation used in VOTable.

BobHanisch: Agreed that this document should be consistent with, and perhaps the defining document for bandpass names. We have a bit of mix right now, with Infrared spelled out and UV abbreviated. Will resolve this.

• Service.HTTPResults : by GuyRixon : Can we rename this one? It's not specific to HTTP and the name is confusing. Service.ResultsMIMEtype?

BobHanisch: Agreed.

• (from EdShaya on mailing list): Constraint should be called something more specific like PlanarConstraint. The description is unclear here.

BobHanisch: As mentioned above, Coverage.Spatial derives from the Space-Time Coordinates metadata and must be consistent.

• • The normal vector (x,y,z) describes the orientation and position of a plane intersecting a unit sphere. It's length is the distance of the plane from the origin; and the plane is oriented perpendicular to the vector. The constraint boundary is the intersection of this arbitrary plane with the unit sphere. One could use zeta, eta to define its orientation and d to give its distance from the origin along the normal direction.
• Convex: by EdShaya : A Convex is just an intersection of Constraints. Since we already specify how to do intersections of regions there is no need for Convex. It is redundant.

BobHanisch: Agreed.

• Relationship: by EdShaya: Because the RelationshipID is separate from the Relationship it would get confusing if a resource is a mirror-of a derived-from resource. It would get even more confusing if we decide to add more relationships in this way. A simple solution is to support mirror-of.resourceID, service-for.resourceID, and derived-from.resourceID instead.

BobHanisch: To me this association of Relationship to RelationshipID is explicit, in that only one RelationshipID is given. But we could perhaps make this even clearer. And, if the RelationshipID should change, it would be preferable to update one entry in the registry rather than three.

• Entity: by RobertPower: In the discussion in Section 3.2, is an entity synonymous to a resource, or is it broader than that? There is a lot of care taken up to this point to define terms (resource, service, organisation etc), and then entity pops up.

BobHanisch: "Entity" comes directly from the Dublin Core definitions, and is explained by way of example as "a person or organization."

• IVOA Identifiers: by RobertPower: The PublisherID and RelationshipID are resource IDs and as such are IVOA Identifiers? Maybe spell this out as done in Sectin 3.1 for Identifier.

BobHanisch: Agreed.

• Being Pedantic: by RobertPower: In Section 3.3 the definition of ReferenceURL: "In general, this should be in a human-readable format", change to something like: "In general, the information should be ..." Otherwise, it could be interpreted as the URL itself should be human readable.

BobHanisch: Agreed.

• Example: by RobertPower: In the Service metadata of the example in Section 6, change the following (note the last one should maybe be http://us-vo.org/metadata/conesearch, since I couldn't find a reference to ConeSearch within IVOA):
  • Service.InterfaceURL http://archive.stsci.edu/sdss/catalog.html
  • Service.BaseURL http://archive.stsci.edu/sdss
  • Service.StandardURL http://www.ivoa.net/Documents/REC/ConeSearch.html

BobHanisch: The first suggested correction is fine. The second, to BaseURL, is not (try it out). As for "ConeSearch" vs. "conesearch" we just need to make sure things are consistent.