Characterisation Data Model RFCThis document will act as RFC centre for the Characterisation Data Model 1.11 Proposed Recommendation. Review period: 01 Jun 2007 to 4 Jul 2007 | ||||||||
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> > | There are two other important documents to check with the model related to existing implementations and the derived XML elements names used for metadata tagging: Utypes. Implementations of this model has been described in the following note, submitted today (August 13th, 2007): http://www.ivoa.net/Documents/Notes/ImplemtationCharacDM/ImplementationCharacterisation-20070813.pdf See http://www.ivoa.net/Documents/latest/ImplementationCharacterisation.html if not available yet. Utypes derived from the UML model are listed and commented in the following note: http://www.ivoa.net/Documents/latest/UtypeListCharacterisationDM.html | |||||||
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Comments
Comments from the Working Group Chairs and Interest Group ChairsChairs should add their comments under their name.Mark Allen (Applications WG)Christophe Arviset (TCG vice Chair)Matthew Graham (Grid & Web Services WG)Bob Hanisch (Data Curation & Preservation IG)Gerard Lemson (Theory IG)Mireille Louys (Data Models WG)Keith Noddle (Data Access Layer WG)Francois Ochsenbein (VOTable WG)Pedro Osuna (VOQL WG)The concepts in the document apply very well to the description (Characterisation) of, for instance, an observation. There is a clever separation into axes with different properties, which makes the complete characterisation possible with few parameters. For instance, the table in page 9 is very useful to identify correctly the concepts for a proper description of a "data set". The figure 2 on the different levels of description is also very enlightening. There are some points however that,not being showstoppers for the Recommendation process, should be considered for improvement, whether in this version or subsequent ones. Other issues are probably more editing than any other thing. - in pg.3 reference is done to the Observation DM. However, it looks like not much work has been going on on the Observation DM. Is the Observation DM going to go ahead, or is it going to be "superseded" by the Characterisation DM globally?. In the former case (Obs DM disappearing), the Char DM should contain all the info that is currently on the Obs DM. In the latter, the difference (or complementarities) between the two should be briefly mentioned. - in pg. 10 (point 3.4.1) mention is done to a combination of UCD and units to "ensure uniqueness and recognition by standard software". This issue has been treated many times, and at the last Beijing meeting it was finally recognised that a set of "BIYECTIVE UTYPES" should be defined for Data Models to be understood. This biyective-utypes were given the name "UFIs" by Jonathan. Despite the fact that they are undefined yet, they resemble very closely the Object Oriented technology attribute naming, i.e., names constructed by dots in between class names. The issue of how to mention actions in the UFIs is also an important issue and a small team has been created to deal with these things (although admittedly, not started to work on it yet). Therefore, this paragraph should either contain a reference to that, or remove the first paragraph. - the whole list of attributes in the Data Model should be clearly made explicit in the document. They should normally correspond to what has been called UTypes during all this time, and they should be inside the document, and not in a separate one. In particular, the UTypes should clearly reflect the UML structure of the DM. The UML is missing a "top level" diagram, where inheritances and associations are clearly seen. Also, the "Axis vs Properties" issue can be solved through proper UML modeling of the DM, and should be done so, in my opinion. Leaving the possibility to traverse the tree upside down (Axis to Properties) or the other way around might make the model unworkable for software handling. The UML and its attributes should be reviewed. - mention is done in 4.4 of the Quantity DM. In my understanding, the Quantity DM effort has been discontinued by the DM group. If this is the case, the reference should be removed. Otherwise, a more detailed reference of how the Quantity DM is affecting this document should be made explicit. - point 5.2 goes again to the UType creation. UTypes (or UFIs in our more "modern" view after Beijing) should not have repetitions in their names. Different model classes don't need to have the name of the parent in their name. In any case, the whole list of the UFIs (or UTypes) should be given in the document with a clear mapping 1 to 1 to the UML diagram that represents them. The Spectral DM could be a good example of how this can be done.
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< < | for modelizing the instrumental and moreover softawre Provenance of the | |||||||
> > | for modelizing the instrumental and moreover software Provenance of the | |||||||
datasets. So I think the next step as we already stated during the first DM
session in Beijing (see my talk there and Jonathan's conclusions) will be to
focus on Provenance...
Now the last point you adress is a vocabulary one. Some people may want to call
all metadata "Characterization" (actually some astronomers outside our
IVOA community allready do when they specify their needs - see the discussions
during spectroscopic workshop last March at your site) including Curation
and Provenance ... It may be the final IVOA choice, but in that case
we have to find a new class name for what is presently called Characterization
which is this part of metadata dealing with the description of the dataset in
the data parameter space....
My personal opinion is that I don't see any good reason to change:
so the future ObservationDM Map could be:
____________ObservationDM
_______Data_______________Metadata
___________________ObsId, curation, Char, Provenance , etc ...
Ray Plante (Resource Registry WG)This is well-written, well-organized, and easily digested--nice work. A few small comments:
Andrea Preite-Martinez (Semantics WG)Roy Williams (VOEvent WG)<--
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