VocabulariesV20RFC < IVOA

---++ Vocabularies in the VO 2 Proposed Recommendation: Request for Comments

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Vocabularies in the VO, version 2, proposes formats and practices to manage hierarchical word lists that need consensus within the VO. See http://ivoa.net/rdf the vocabularies currently in use or under consideration.

Note that this is *not* &ldquo;Semantics in the VO&rdquo;, i.e., further applications of RDF (e.g., full ontologies) are by no means excluded by this specification.

Latest version of Vocabularies in the VO 2 can be found at:
   * https://ivoa.net/documents/Vocabularies/20210114/
A build of svn trunk with some typos removed is available at https://docs.g-vo.org/Vocabularies.pdf

---+++ Reference Interoperable Implementations

Vocabularies of the type described here are in use by several existing standards:

   * Datalink (the semantics column)
   * VOTable (TIMESYS time scales and reference positions)
   * VOResource (relationship types, content levels, content types, date roles, prospectively the subject keywords)
   * SimpleDALRegExt (under review: product types)
   * VODataService (under review: messengers)
The code managing the RDF repository is available at https://volute.g-vo.org/svn/trunk/projects/semantics/voc-source

Implementations on the consumer side:

   * stilts' VOTable validator uses vocabularies to check the TIMESYS attributes (this gives a simple example for how to deal with IVOA vocabularies in Java)
   * pyVO will use the Datalink vocabulary for query expansion in the bysemantics method (https://github.com/astropy/pyvo/pull/241). This gives an example for how to use vocabularies from Python
   * [[https://dc.g-vo.org/sembarebro/q/ui/fixed][Sembarebro]] is an example for how to use vocabularies from Javascript ([[http://svn.ari.uni-heidelberg.de/svn/gavo/hdinputs/sembarebro][code]])
   * Another example for using IVOA vocabularies from python is the implementation of the gavo_vocmatch ADQL User Defined Function in DaCHS. See http://dc.g-vo.org/tap/capabilities for a definition of the UDF ([[http://svn.ari.uni-heidelberg.de/svn/gavo/python/trunk/gavo/adql][Code]], around line 526)
   * A somewhat more complex use case is [[https://blog.g-vo.org/semantics-cross-discipline-discovery-and-down-to-earth-code/][using the UAT hierarchy in mapping metadata]], which again contains examples for vocabulary use in Python.
On processes defined:

   * several VEPs have been run
   * a PEN has been produced for vocabulary adoption: https://ivoa.net/documents/uat-as-upstream/20201117/ &ndash; it is probably a good idea to give this a brief look, too, when reviewing Vocabularies 2. Perhaps these Vocabularies 2 should give some constraints what must minimally be addressed in this kind of document

Plans for the consumer side:

   * The RofR publishing registry validator should use the VOResource vocabularies; we expect this to happen during RFC.

---+++ Implementations Validators

The vocabulary process itself is in some sense self-validating because the input files are parsed and mangled. A &ldquo;deeper&rdquo; validation (&ldquo;are these concepts any good?&rdquo;; &ldquo;can people work out from a description what is and what is not within the concept?&rdquo;) is probably beyond what automated validators can do.

As to the external interface, common RDF validators can be used to check the syntactic correctness of our artefacts, for instance the [[http://www.w3.org/RDF/Validator/][W3C RDF validator]].

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---++ Comments from the IVOA Community during RFC/TCG review period: 2021-03-22 through 2021-05-03

The comments from the TCG members during the RFC/TCG review should be included in the next section.

In order to add a comment to the document, please edit this page and add your comment to the list below in the format used for the example (include your Wiki Name so that authors can contact you for further information). When the author(s) of the document have considered the comment, they will provide a response after the comment.

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---++ Comments from TCG member during the RFC/TCG Review Period: 2021-03-22 through 2021-05-03

WG chairs or vice chairs must read the Document, provide comments if any (including on topics not directly linked to the Group matters) or indicate that they have no comment.

IG chairs or vice chairs are also encouraged to do the same, althought their inputs are not compulsory.

---+++ TCG Chair & Vice Chair

---+++ [[IvoaApplications][Applications Working Group]]

---+++ [[IvoaDAL][Data Access Layer Working Group]]

---+++ [[IvoaDataModel][Data Model Working Group]]

I've a few comments that do not requires document changes:
   * P6 The UCD-Vocab binding could be more detailed
   * P7 I really appreciate the reading guide
   * P10 Links between DM and vocab need further reflexions
   * General: How a client can retrieve the vocabulary a word refers to? <br />A client getting BARYCENTER as TIMESYS@reflocation has no way to know that the word BARYCENTER is part of http://ivoa.net/rdf/refposition
   * P34 A3: is the volute URL supposed to survive Vocabukary 2.0
and a few non blocking suggestions from a novice reader
   * P8 CURIE: a footnote (https://www.w3.org/TR/2010/NOTE-curie-20101216/) would help
   * P14 2.3 RDF triples: a foornote (https://www.w3.org/TR/rdf-concepts/#section-triples) would help as well
   * P18 Examples of valid and non valid RDF URIs would help.
Approved<br />-- IVOA.LaurentMichel - 2021-04-22
---+++ [[IvoaGridAndWebServices][Grid & Web Services Working Group]]

---+++ [[IvoaResReg][Registry Working Group]]

---+++ [[IvoaSemantics][Semantics Working Group]]

---+++ [[IvoaDCP][Data Curation & Preservation Interest Group]]

---+++ [[IvoaTheory][Education Interest Group]]

---+++ [[IvoaKDD][Knowledge Discovery Interest Group]]

---+++ [[IvoaSS][Solar System Interest Group]]

---+++ [[IvoaTheory][Theory Interest Group]]

---+++ [[IvoaVOEvent][Time Domain Interest Group]]

---+++ [[IvoaOps][Operations]]

Accept. -- IVOA.MarkTaylor - 2021-03-20

---+++ [[IvoaStdsDocsProc][Standards and Processes Committee]]

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---++ TCG Vote: TBD

If you have minor comments (typos) on the last version of the document please indicate it in the Comments column of the table and post them in the TCG comments section above with the date.

| Group | Yes | No | Abstain | Comments |
| TCG | | | | |
| Apps | | | | |
| DAL | | | | |
| DM | * | | | |
| GWS | | | | |
| Registry | | | | |
| Semantics | | | | |
| DCP | | | | |
| KDIG | | | | |
| SSIG | | | | |
| Theory | | | | |
| TD | | | | |
| Ops | * | | | |
| <nop>StdProc | | | | |

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This topic: IVOA > WebHome > IvoaTCG > VocabulariesV20RFC
Topic revision: r4 - 2021-04-22 - LaurentMichel