Agenda - see also: IRC log, day two minutes
meeting room right side
meeting room left side
tbl: meeting of a group of people interested
in SW in the Cambridge area
... 15 people interested
... no particular agenda
... mainly a social thing
... discussion, brainstorming
... in this room (Kiva)
Guus: short round of introductions
Alistair: we have several implementations of SKOS now
Jon: picked up on SKOS at Dublin Core Madrid workshop
Bernard: U. Manchester is adding SKOS to COHSE
Guus: interoperability of vocabularies is core to our work at Vrije University
Diego: my research work is on semantic search
Fabien: my research group is interested in graph-based reasoning on SemWeb
Ivan: every day I take a tram that goes by Guus' office
tbl: i'm not here as W3C director.
... interested in the discussions on RDFa and recipes ("slash")
...I taught a 1-week course [2 weeks ago] and one of the biggest problems was how to configure apache
... if it came out-of-the-box with application/rdf+xml support things would be a *lot* easier
RalphS: the activity of this group is very
important, great impact
... very busy, reduced dedication to this group
...but hope to increase my time in SWD again
[Tom calling from Berlin, Elisa calling from Los Altos]
Tom: project looking at model-based metadata; includes Dublin Core and eventually SKOS
Elisa: working with organizations who are keenly interested in metadata about their ontologies ... core business of SandPiper is ontology development
Guus: three objectives of this meeting
... 1) skos use cases: discuss them
... 2) as a result, obtain a list of requirements for SKOS
... 3) review issue list, priorize them, select critical ones
Antoine: 12 use cases in the document
... there are more than 20 contributions
... some are not edited (yet), but available at the wiki
Antoine: thinks the response of the community
... will summarize each one of the UC next
Guus: two different hierachies for the same thesaurus, is this a requirement?
aliman: multi-hierarchy is an important requirement
Guus: shows an example of the getty vocab
Guus: google for 'tgn getty', then enter 'boston'
Guus: two record types: administrative and geographical, non exclusive
... (shows Utrecht next)
Guus: looks up for an example of a record with two types
Antoine: complex lexical info in the context of this application
Guus: Boston has several alternative names
Guus: Getty shows English, Vernacular, and Historical names
... e.g. Tokyo has 'Edo' historical name
Aliman: multilingual labels are already
... but language is not enough in some cases (see the Boston and Tokyo examples)
... the issue is there are different scripts for some language, but only a language tag
Alistair: potential issues with cardinality constraints and preferredLabel properties if there are multiple scripts in which the label might be written
Guus: this is probably out of scope of this WG
ivan: this WG should not worry about this issue. Maybe forward the issue to the RDF core WG
RalphS: asks for clarification of the multi-hierarchy issue
Alistair: a conceptual node may have more than one parent
guus: back to the issue of making a statement about a label
aliman: we should provide a framework to allow that
guus illustrates his point with an example in the whiteboard
Guus: how would we say the label "Edo" is valid only between 1600 and 1800 AD ?
Alistair: annotation properties
aliman: when you use an annotation propierty,
you are not limited to a literal value
... you can use a resource as a value of the annotation property. Model annotation as an n-ary relation.
ivan: is this a possible use of reification?
guus: seems to be 2 options: to reify, or to lose information
timbl: another option is to put the statement in another document
Alistair: the old issue notes a place-holder item for this
... "SKOS does not provide support for ... any type of annotation associated with a non-descriptor"
<timbl> http://dig.csail.mit.edu/2007/Talks/0108-time-tbl/ are a few slides about options for modeling things which vary with time
Guus: not sure this is the same thing
ACTION: Alan write up the preferredLabel modelling issue [recorded in http://www.w3.org/2007/01/22-swd-minutes.html#action01]
AlanR: just joined the WG representing Science Commons ... active on HCLS IGUC 2: Iconclass
... has descriptor concepts and non-descriptor concepts
Guus: this case helps define SKOS scope
... Iconclass is a grammar
... permits adding things to parts of the vocabulary
... I'd like to make this feature out of scope for SKOS
... e.g. KEY; it's not pre-defined where in the vocabulary this is used
Antoine: finding modifiers while browsing a vocabulary -- "post coordination"
aliman: this mechanism allows to create new concepts by combination of existing concepts
Guus: shows an example of the vocabulary ("Animal")
aliman: this is related to the "qualifiers" of the MESH medical vocabulary
Alistair: terms in MESH have flags that indicate they can be used with an additional qualifiers vocabulary
<aliman> http://www.w3.org/2004/02/skos/core/proposals.html#coordination-8 example of coordination
Alistair: ... e.g. 'aspirin' combined with 'sideEffects' means 'sideEffectsOfAspirin'
Alistair: BLISS classification scheme has similar aspects
Antoine: we lost the possibility to attach
... cannot represent hierarchies of qualifiers
aliman: ambiguity can arise from the use of qualifiers
Alistair: in my master's thesis I conclude that it is an application-specific decision whether order of coordination is significant
aliman: if you don't have a mechanism to attach the qualifier to particular individuals
Guus: Iconclass also has a notion of 'opposite', or counter-example, done by doubling the letter; e.g. 25FF
<aliman> Examples of using bliss classification http://www.sid.cam.ac.uk/bca/bcclass.htm
Guus: this feature is also used in Iconclass to do male-female distinction
Antoine: 13,000 concepts
... in this vocabulary
... qualifiers allow to reduce the number of concepts
... indexing can use multiple concepts
<scribe> ACTION: Antoine to provide more use cases of uses of qualifiers [recorded in http://www.w3.org/2007/01/22-swd-minutes.html#action02]
Alistair: library world talks about "synthetic" and "enumerative" classification schemes; "synthetic" scheme is meant to be used in combinations to synthesize categories
[15 minute coffee break]
<aliman> http://dlist.sir.arizona.edu/651/ Core requirements for automation of analytico-synthetic classifications
<aliman> (I just found this paper, looks highly relevant to preceding discussion.)
antoine: we have to decide at some point what goes into the document
guus: we should keep the overview and the details of examples
ralph: features in the use cases that are important for skos has to be brought out from the examples (for those who do not know the details)
alistair: we could move the examples from the vocabulary to the example, but what ralph said made me think again...
guus: it is good to have that on our list...
UC 3 - Medieval illuminated manuscripts (mandragore)
antoine: next use case an integrated view to
... there are collections and bridges among these
... we always have info on which vocabularies are used
... an issue of alignment of vocabularies
... it uses the iconclass vocabulary
... and another one that comes from the French national library
... the latter is 15000 subject, simple labels (simple and alternate)
... it is probably a flat list, and they introduce a set of classes for browsing purposes
... you got between 15000 descriptors, and each is linked to a class that is more general
alistair: is it essentially a tree level hierarchy, but you can use the descriptors on the bottom only
antoine: yes, only the leaves of the tree can be used as descriptors
guus: this is a feature I have not distilled
... this problem of representing mandragore
... there are 2 issues coming out: (1) requirement for mapping, you need equivalence
... (2) you have the notion of abstract classes
... things that are not for indexing
Guus: abstract classes appear in AAT also
alistair: i think it is a use cases that has
some basic requirements for vocabulary mapping among
... there is also a requirement to map between combination of concepts
Alistair: "11U4 Mary and John the Baptist ..."
alistair: 11U4 in the description
... i think that will be a common requirement
antoine: the mapping points that there could
be a link between the non descriptor items
... a descriptor on the one side and a qualifier on the other side, the latter is never be found as a descriptor
guus: is it fair to say we have a mapping requirement and two basic requirements
scribe: with respect to the conjunction type of thing, that is an issue (or a requirement)
alistair: it comes up often in my
... there is a british standard wg rewriting the thesaurus standard
... working on how to represent mapping between thesauri
... i would think that they will come up with something how to model it
bernard: is there a requirement to map the
iconclass to mandragore to identify the ??
... it seems that mandragore is a different type of mapping
Alistair cited ISO 2788 parts 3 and 4 (under development) work on mapping
guus: rephrase the question: do we need more specific than broad and narrow, ie, owl or rdfs vocabulary
bernard: yes, this is what I am asking
... what is the broader term of XX
alistair: there is a browser for mandragore, can we see how this looks like?
antoine showing the mandragore browser example
antoine shows the iconclass vocabulary, one can see the vocabulary and the specialization of the concept
scribe: on the right are the images from the
collection (from the BNF) which have not been indexed
... you browse your vocabulary, then you have access to the images
alistair: can you browse against the mandragore images only?
alistair: when you do a mapping to mandragore, do you use a second level only?
Antoine: there are 15,000 alignment relations in the mapping
guus: I try to summarize, three things
... (1) need for an equivalence mapping
... (2) a less or more specific mapping, should it be more specific than broad/narrow
... (3) links between compostionals
... we recently linked a nist vocabulary for video tracking
... we got into a similar situation
... we got both the conjunctive and disjunctive form
... may be it should be a requirement, or maybe we can handle outside skos
ralph: there a reference to optional rejective
... is that from iconclass?
antoine: this comes from the French vocabulary
ralph: guus showed the double letter example, is it similar
antoine: they are more similar concepts, synonyms
guus: it is quite similar to preferred and non-preferred label
"optional rejected form" means "synonym but deprecated"
alistair: when it comes to mapping
requirement, we need to have in mind of the functionality
it is used for and focus on that
... that might help us in passing by other representations
guus: in this particular domain mappings are
the only thing that adds something to the existing
functionalities to musea
... if you open up the collections to browse to other vocabularies that you get new things
... mapping is 100% crucial,
... the only added value, and a big one
... in medicine it may be different
UC 4 - bio-zen
antoine: 4th example bio-zen
... wait for AlanR to come back on that one
UC 5 - multilingual agricultural thesauri... the 5th use case: semantic search accross multilingual thesauri (agricultural domain)
alistair: that may be like a union
... the last example in the use case they use the mapping vocabulary as it is right now in skos
... it also has 'and or not'
... the second example is exactly an 'or'
guus: ie, they also have the 'and or not' in their usage?
bernard: the more these vocabularies are mashed, they have similar like narrow and broader
alistair: these can be ambigous...
guus: we already have this on the list of the issues (whether we need to represent a specific semantics to broad and narrow)
<scribe> ACTION: guus to check that this issue of more specialization than broad/narrow is on the issues' list [recorded in http://www.w3.org/2007/01/22-swd-minutes.html#action03]
guus: you can say we build into the skos
vocabularies that we define, eg, two subclasses
... or we can say that we leave that to the vocabulary, the authors has the guideline to present this as a subproperty to broad/narrow
... the issue is to resolve this
alistair: ie, if people want to do more specific, how would they do it?
guus: yes, and whether this is part of the skos vocabulary or not
Ivan: were problems with representing multilingual scripts found?
... is there enough in RDF to represent this?
Alistair: there were some interesting language problems in the Chinese mapping
Antoine: but I think they succeeded in representing everything they wanted to represent in RDF, though they needed more than SKOS
<aliman> http://www.fao.org/docrep/008/af241e/af241e04.htm a document about mapping between agrovoc and chinese agricultural thesaurus
guus: term-to-term relationship?
antoine: the problem of having several labels for the same concepts that comes up, they want o be able to line up the literal translations to one another
guus: why not use for each preferred and alternative lables
alistair: the the preferred label in chinese may be the third alternative example in english
timbl: cat translates to 'chat' in French, you have to label in french
alistair: you are making a link between translations and labels
antoine: a concept in one vocabulary has a
latin name for the pref label, and an alternative label the
... the same in the french versions
... and you want to point ot the fact to translate from the two alternative labels
guus: then the latin is a lingua franca
alistair: another thing they wanted that the label in French has been derived from that and than alternative label in English
guus: we may have an issue of relationship of
... not clear to me what to do with this
alistair: we have to be careful with a use
case like this is what they do to exactly with this
... why do they use it
<scribe> ACTION: antoine to capture the issue on capturing relationships between labels [recorded in http://www.w3.org/2007/01/22-swd-minutes.html#action04]
Antoine: e.g. acronym link
... an example of a semantic relationship between labels
UC 6-7 - tactical situations, product life cycle
antoine: use cases 6 and 7 are similar on
... representing quite simple vocabularies, one is on tactical situation objects
... a list of unstructured terms
... each term has some label and a note
... when it should be used
... the support life cycle is similar
ralph: in #6 it was difficult to see what it says about skos
alistair: me too
... this is not the sort of use case i am familiar with
antoine: i tried to interpret it, but apart form simple labelling i did not find anything
alistair: we could ask them what they want to do
guus: this is what they have...
ralph: maybe we want to ask submittors to point at the wg on areas they want additional things
alistair: use case 7 actually adds a question
mark on skos (or owl)
... it is not clear why they want to skos
guus: i could think of reasons
antoine: they were search of standard ways
guus: the problem with use case #7 that it is
out of scope
... or am i misunderstanding
ralph: it would be interesting question to ask them what they want skos for
bernard: may be a marketing issue
<scribe> ACTION: antoine to contact the submittors of #7 to see what they want to use skos for (as opposed to, say, owl) [recorded in http://www.w3.org/2007/01/22-swd-minutes.html#action05]
alistair: it seems that they have a requirement to capture lots of things, that may need to extend skos
antoine: no, they really need only flat
... they need a structure to represent a natural language representation without a reasoner
UC 8-9 - GTAA (audiovisual archives) and CHOICE@CATCH (radio/TV)
antonie: number #8 gtaa web browser, accessing
... want to provide the user with a sophisticated vocabulary
guus: there is an archive for tv and radio
... they do annotation inside the content but also coming from broadcasting companies
... on the top level there are 8 different facets
... and several of the sub hierarchies have separate classifications
... and that is the whole thing
... they are specific for a facet
alistair: there is a thematic and a named hierarchy, and they are orthogonal
guus: we can get test cases out of it
ralph: 'only keyword and genres can also have broader/narrower relation', is that a restriction?
guus: this is a very flat structure, this is not really a restriction
antonie: use case #9, another use of the same
vocabulary of use case #8,
... using a special algorithm that provides the user an indexer
... the idea is to explore the different links in the thesaurus to rank the concepts
... if you have to index a document with a set of candidate terms, if the thesauri includes these terms, than that hierarchy is also presented
guus: I would have personally merged #8 and #9
antoine: #9 provided in a functional
... adding a representation to an applicaiton is nice
guus: people in computer science like
... but these people like to manually check
ralph: even though it does not add anything technically, it adds a new aspect, good for 'marketing' reasons
alistair: if you look a traditional model, you
manually build a vocabulary and index
... in this case the vocabulary is done manually, but an automatic indexing is good
... a use case document should have a business model section to show how different scenarios are used
guus: summary: #9 does not add anything to the requirements, but is an interesting use case scenario to keep
alistair: applications might want the integrity of their data, and expressing the constraints is a requirement
guus: there is already and issue on the level of semantics that skos has
<scribe> ACTION: alistair to summarizes the aspects of semantics of the skos data model [recorded in http://www.w3.org/2007/01/22-swd-minutes.html#action06]
JonathanRees: I'm part of Science Commons
alistair: a question on #8, relationships on
terms between facets were computed
... question is how were these computed?
guus: the general problem was that there were
lack of relationships
... but I do not think there were much semantics
alistair: it also says the precomputed terms were not part of the iso standards
guus: good question, I do not know
<scribe> ACTION: guus to check with veronique on the terms being outside the iso standard [recorded in http://www.w3.org/2007/01/22-swd-minutes.html#action07]
UC 4 - bio-zen
antoine: use case #4, bio-zen ontology
... the main point to represent these medical vocabularies, keeping all the infos that are useful for application
... the application was not really detailed
... gene ontology and mash are the two examples for applications
... it has an example of representation of a term
... the main point is the fact that the representation they mix all kind of different of metadata vocabularies
... they created some sort of metamodel using owl, and uses pieces of other vocabularies
... they use all these meta models to represent the medical vocabularies
... they use, eg, dublin core plus skos terms together
... they created an owl specification to mix these metamodel features
guus: why there was within the definition
there is a representation of the part of relationship
... does the mesh have its own hierarchy
alan: 'is a' is not 'part of', careful about that
guus: in skos we use the broader and narrower terms which are less defined
alan: obo originates in the gene
... the latter has is a and part of relationships in it
... there has been a number of threads using this
... one thread is to translate obo to other formats, people used, eg, skos
... they have to decide where broader, etc, are used
... these actually threw away information but they are part of skos
... from my understanding at the time at least
... there is an effort to translate this into owl
... second thread of discussion is the 'quality' of the whole thing
<Elisa> There is a recently released related portal - Daniel Rubin and his group have created this and are working to develop it as a part of their NCOR work: http://www.bioontology.org/tools/portal/bioportal.html
alan: what can be related to what, what are the description of that, more philosophical stuff
guus: some people make subproperties from,
say, skos broader
... then you do not throw away things
alan: i had the issue on putting it with owl-dl
guus: that is a separate issue on the agenda (relationship to owl-dl)
Alan: Matthias is asking that as we fiddle with SKOS, we try to keep it OWL-DL compatible
Alistair: it's already not OWL-DL
alistair: if you go into library sciences, you
will find papers on classification
... people there define fundamental facets, time, space, etc
... there are discussions on what these fundamental facets are
... that might come to the skos spec
... but if you want to do that, this should be done as an extension of skos (in my view)
guus: b.t.w., the relationship to owl-dl
should be part of our issues list, not requirement
... maybe if we define a set of constraints, that might lead to skos-dl...
... but this is a topic for discussion
alistair: it is tricky, extension by requirements is one of the major way of extending skos, and all of those are annotation properties, and that leads to problem
<scribe> ACTION: alistair to rephrase the old issue of skos/owl-dl coexistence and semantics [recorded in http://www.w3.org/2007/01/22-swd-minutes.html#action08]
bernard: it was good in the owl days to have implementations submitted, too
guus: for the moment it is good to collect the
information, it is good to use them as test cases
... but this group is much smaller than the old owl group, and we have a resource problem
alistair: there are two wiki pages, and the shiny new skos web site: SKOS home page
alistair: the idea that anyone who has implementation should be able to add it
UC 10 - BirnLEX
antoine: use case #10 birnlex, lexion for
... aims at providing several vocabularies
... they are the same as the bio-zen use case
... there is a mixture of different metadata models, skos, dc, foaf, etc
alistair: all they want is the some of the
properties like pref label, alt label, not in the structure
... if skos has good annotating support, people may just want to use that
guus: i interpreted this as having a lot of
need to various type of relations
... there are many things in the examples term relations with other semantics
alan: the argument is that there is a desire
of the part of type of relationships that we may need in
... ie, people insert tags into the rdf labels,
... shows the importance of this issue
Alan: the BIRNlex use case may bring in issues for our vocabulary management work
alistair: this is a bit of annotating just about everything
UC 11 - OBI (Ontology for Biomedical Investigation)
alistair: they do not want skos broader and
... it is more that they want all type of documentation/annotation support
guus: the issue here is that you have your
... how to document/annotate various concepts
... and what skos give you on that
<scribe> ACTION: alan to write down the general documentation requirements, in particular to those that are related to literal values, and how to represent that in skos [recorded in http://www.w3.org/2007/01/22-swd-minutes.html#action09]
antoine: use case #11 quite similar
... I have not read it in much details
... it is once again to represent all these various vocabularies and linking/importing skos concepts to an 'own' ontology
... and extending skos relations
guus: my proposal: there are still use cases
... we have to include facilities to evaluate use cases
... we should go through the list of the requirements and see if we can refine this
... and go through the issues' list
SKOS Requirements (sandbox)
-> http://www.w3.org/2006/07/SWD/wiki/UCRMaterial?action=AttachFile&do=get&target=ucr-20070117.html#SKOS SKOS Requirements sandbox
--R0. Information accessible in distributed setting
Guus: is this a requirement on SKOS?
Antoine: doesn't seem to change anything about SKOS or what it represents
Guus: seems to be a general Web requirement
Ralph: comes with RDF and the Semantic Web
RESOLUTION: drop R0. Information accessible in distributed setting as not SKOS-specific
--R1. Representing relationships between concepts
Bernard: "displaying or searching concepts"
might give the impression of constraining our scope
... e.g. excluding annotation
Guus: how about "representing relationships
... the ability to represent hierarchical and non-hierarchical relationships between concepts
-- R2. Representing basic lexical values (labels) associated to concepts
Antoine: "basic" as in "simple" as compared to more sophisticated scope notes
Guus: basic lexical _information_ or do you
really mean to restrict to _labels_ ?
... "access to" not needed
-- R3. Representing links between labels associated to concepts
Guus: we have an issue related to this
... this requirement may change after resolving the issue
Alistair: we could suggest a point of view
without making a hard requirement
... while reviewing all these requirements today
Guus: I suggest that any requirement with a related issue be marked as "soft"
-- R4. Representation of glosses and notes attached to vocabulary concepts
Antoine: "notes" means "scope notes"
Guus: so use the well-known term "scope notes"
Antoine: should we include administrative notes?
Jon: suggest "glossaries" instead of "glosses"
Guus: I thought there is a distinction between a glossary and a scope note
Alistair: what's the difference between
'gloss' and 'definition', then?
... SKOS hasn't used the term 'gloss' previously
Guss: "representation of textual descriptions ", with text mentioning definitions, scope notes, ...
Tom: suggest "Representation of lexical information in multiple languages"
Bernard: multiple _natural_ languages?
Guus: yes, good addition
-- R6. Descriptor concepts and non-descriptor ones
Guus: distinction between concepts intended to be used for indexing and other concepts?
... what I had in mind was the existing skos:subject
... some concepts cannot be used as subject relationships
Guus: qualifiers are still relevant to
... e.g. AAT vocabulary
... Furnishings ... furniture ... <furniture by form or function> ... screens
... the terms in <...> are not meant for indexing
Alistair: many folk would not consider the
<...> to be concepts; they call them "node
... they are labels for a grouping of concepts, the groupings are called 'arrays'
... they say the node label does not represent a 'concept'
... in the British standard it is quite clear that the node labels are only used in a certain way
... but AAT adds things to the thesaurus beyond the British standard
... it's just a matter of us wording this requirement correctly
... consider Mandragore; you're not supposed to use things from levels 1 and 2
... but the British standard demonstrates a requirement to be able to label groupings
Guus: propose to rephrase as "the ability to distingish between concepts to be used for indexing and for non-indexing"
Bernard: is this really a requirement or just an issue?
Guus: is this in the ISO standard?
Alistair: no, in ISO thesaurus any concept can
be used for indexing
... there's no a-priori reason why something not intended for indexing in one context would be inappropriate for use in another context
Guus: suggest R6 is a soft requirement
... and add a new requirement having to do with grouping
... "the ability to include grouping constructs in concept hierarchies" -- as a soft requirement
Alistair: hierarchies are not the only place
where node labels can be used
... node labels are also used in related terms
<aliman> see z39.19
-- R7. Composition of concepts
Guus: is this like conjunction and disjunction?
Alistair: the terms 'conjunction' and
'disjunction' don't really make sense as we're not talking
about sets of things
... the classical way of talking about this is to talk about 'coordination', and 'coordination of things'
... I'm afraid to use set-theoretic language, as this would be jumping the gun
... we're not talking about True and False or sets, rather we're talking about concepts
... 'compound concepts' is a term used in the thesaurus world
... 'post-coordination' usually means that things are coordinated at search time but it typically really just means queries with more than one thing
... I don't recommend referring to pre- or post-coordination
Guus: I recommend linking 'coordination' to an explanation
Alistair: I'd be happy using 'composition' rather than 'coordination'
Guus: let's categorize into 'candidate requirements' and 'accepted requirements' (rather than 'hard' and 'soft')
-- R8. Vocabulary interoperability
Guus: mapping at the level of equivalence,
more specific, less specific
... further things under discussion
... suggest dropping this, as we need to be able to test
Ralph: is R8 the general case and R12 a specific case?
Jon: I have another use case; our system
supports the expression of relationships between terms in
vocabularies we own and terms in vocabularies we don't
... the reciprocal relationship would need to be endorsed by the owner of the other vocabulary
Guus: I can make equivalence statements in my
own ontology and others can choose to use mine or not use
... valid to have different statements about mapping and determine to which you commit
Jon: imagine two indexing systems but a single retrieval system
Alan: a search for A should include B but not vice-versa?
Fabien: is this specific to equivalence or is it a filter on the source?
Guus: back when we did OWL, I had to spend a
long time defending owl:imports
... this may be outside the SKOS language, at a different level of the SemWeb stack
Jon: this is not about trust but about representing the intent of the thesaurus writer
Guus: but it's at a reasoning level
Alistair: we refer to 'SKOS concepts' and 'SKOS concept schemes'; perhaps we can also talk about 'mapping schemes'
Guus: like provenance?
Bernard: why isn't a concept scheme the same as a mapping scheme
Alistair: they're handled differently by
... an application wouldn't display a mapping scheme as a hierarchy
Bernard: but if you dereference all the concepts in a mapping scheme wouldn't you end up with a concept scheme?
Alistair: there's current a loose
recommendation that two concepts in a single concept scheme
do not share a label
... this might be expressed as a logical constraint on a concept scheme
... but this constraint would be inappropriate for a mapping scheme
... if someone wants to capture in their RDF graph that there exists a set of mappings that he authored ....
... a concept scheme has a notion of 'containment'
... different integrity constraints if you're just collecting some mappings
Alan: if you use owl:sameAs, you're making a
... but the author of a vocabulary might want only a one-way assertion
Antoine: is related to the issue Sean raised about containment
Bernard: is there something about R8 that is
not included in R12?
... "it shall be possible to record provenance information on mappings between concepts in different vocabularies"
RESOLUTION: R8 reworded to "it shall be possible to record provenance information on mappings between concepts in different vocabularies"
Tom: we use "vocabulary", 'concept scheme', and 'SKOS model'; let's stick to one term
Guus: I propose we drop 'concept scheme' and use only 'vocabulary'
Alistair: the ISO standard does not
distinguish between term-oriented and concept-oriented; I
made up this distinction
... you _can_ talk about whether the data model is term-oriented or concept-oriented, but not the vocabulary itself
Guus: consider a 'bank' vs. 'financial
... 'bank' implicitly defines a concept, implicitly it's a lexical label
... consequence for a thesaurus is that the term 'bank' cannot be used anywhere else
... in practice this distinction is useful, which is why I'd prefer to not use the term 'concept scheme'
... 'vocabulary' is more general and makes less commitments
Tom: R10 is really talking about the extension
of the SKOS vocabulary, not the SKOS model
... could be confusing if we use the term 'vocabulary' generically
Alistair: the 'concept scheme' idea came from DCMI
Ralph: it's probably easier to refer to "the SKOS vocabulary" and "a SKOS concept scheme" to differentiate between the SKOS terms and a thesaurus written using the SKOS terms
Bernard: let's define terms near the start of the document
Antoine: I tried to consistently use 'vocabulary' for applications of SKOS and 'model' for SKOS itself
Alistair: there are implicit integrity constraints currently expressed only in prose
Tom: this is a big question that deserves more
thought, let's not decide now
... SKOS model is like an application model (in DCMI world)
... R10 talks about extending both the SKOS model and the vocabulary of properties
Guus: for the time being, let's distinguish between the terms in the SKOS vocabulary and the application terms that use SKOS
Guus: for now, let's use "SKOS vocabulary" and "concept scheme", respectively, for these two
-- R9. Extension of vocabularies
now called: "R9. Extension of concept schemes"
Alistair: how do I express that I want to import another concept scheme into my own, or import only a part of another concept scheme?
Bernard: why import, just reference?
Alistair: how does a browser know the boundary of a new concept scheme?
Bernard: related to Protege issue of how to represent externally-defined items
Guus: do we include maintenance properties,
revision information, etc.?
... I suggest we add a requirement related to versioning information
Bernard: R9 is about tools
Ralph: I suggest we keep the vocabulary management work, including versioning, as a separate task and not mix it into SKOS right now
Jon: example; replacing a single term with two
... not necessarily establishing a broader/narrower relationship but dropping the old term
Guus: we handle this in OWL by deprecating old terms
Alistair: my approach is to worry first about how to represent a static model
Guus: suggest deferring versioning questions to separate vocabulary management work and later evaluate whether any SKOS-specific properties are needed
Alistair: we have requests to be able to
define concept schemes as 'we use everything in that scheme
with the following additions'
... Alistair: I need to find a better use case to motivate this
-- R10. Extendability of SKOS model
now "R10. Extendability of SKOS vocabulary"
Guus: means "local specialization of SKOS
... propose to rename this to "local specialization of SKOS vocabulary"
... get this for free
-- R11. Attaching resources to concepts
Antoine: this is skos:subject; annotating resource
Fabien: inverse of dc:subject?
Alistair: skos:subject is dc:subject with a range constraint
Guus: propose to rename this to "Ability to
represent the indexing relationship between a resource and
a concept that indexes it"
... I suggest this is a candidate requirement
-- R12. Correspondence/Mapping links between concepts from different vocabularies
now "... different concept schemes"
Bernard: related to mapping between labels in different concept schemes; that can be a separate requirement
Guus: at a minimum, equivalent, less/more specific, and related
Alistair: also composition
Alan: is 'related' a superproperty of 'broader' or 'narrower'?
Alan: please document this explicitly in the spec
Guus: propose a new candidate requirement: Correspondence mapping links between lexical labels of concepts in different concept schemes
-- R13. Compatibility between SKOS and other metadata models and ontologies
Antoine: may not bring any additional requirements on representational features
Guus: what other models do we want to be compatible with?
Alistair: Dublin Core
... note that changes have been made to Dublin Core specifically to align it with SKOS
<Elisa> Another metadata standard we should consider here is ISO11179
Elisa: ISO 11179 is another related standard,
on which Daniel Rubin and I have spent time recently
... Daniel is interested in 11179 because many biomedical ontologies use it
... by mapping 11179 to SKOS we bring a lot of those into the RDF world
Alistair: 2788 is a thesaurus standard and is
very different from 11179, which is a metadata model
... there is a particular part of 11179 that is intended to talk about classification schemes
... it's obvious how SKOS and that part of 11179 relate
Alan: what does "compatible with" mean?
Bernard: does "compatible with" mean "does not violate the [Dublin Core] abstract model"?
Ralph: what sort of test cases could we construct to decide "is compatible" or "is not compatible"?
Alistair: could we translate a data instance using 11179 to a data instance in SKOS? how much data loss? how much data loss in transforming back?
Alan: the scope of 11179 is much larger than that of SKOS
Guus: it would be good to identify specific
... e.g. 2788, 11179 [part 3]
Alistair: 5964 (multilingual)
... I'd put 2788 as a stronger requirement than 5964
... interpretation of 5964 is harder
Alan: is SKOS a "metadata model"?
Guus: propose omitting the general requirements R13 and R15 and adding specific requirements for 2788, 11179.3
Alan: is all of 11179.3 relevant to SKOS? there's a lot of stuff in there
Elisa: I am happy to help narrow the
... and the US contingent in the 11179 group are physically close to me
-- R.14 OWL-DL compatibility
Guus: we can talk about a SKOS representation that is OWL-DL compliant
Alan: make it formal that annotation [sub]properties are allowed?
Guus: we have to be sure that we can complete
our deliverables without requiring another WG to be
... we can make comments to the OWL comment list about annotation properties
Alan: there's a partial workaround available to SKOS
Ivan: what does DL compatibility mean when you
have a processing model that includes some rules into
... regardless of annotation properties, SKOS is already out of DL
Alistair: the rules don't have to be used
-- R.16 Checking the consistency of a vocabulary
Guus: issue raised earlier about semantics
[I think Tom's suggestion is agreed implicitly]
Jon: I've been updating the sandbox wiki in realtime
Guest: Steve Williams, hyperforms
technologies, participating in W3C 2-3 in binary XML
...interest in semweb, relatied technologies, interested in AI.
Guest: opera software, interested in semweb
since 98, bumped into danbri, then graduate student of
astrophysics, then hired by opera, mostly programmin,
chaals getting me into more on semantic web.
... responsible for my opera foaf stuff
Current issues list: http://www.w3.org/2006/07/SWD/wiki/BestPracticeRecipesIssues
guus: moving on to discussion of recipes for publishing RDF, have as input recipes document from SWBPD, incomplete document, Jon action to generate issues list, now on wiki
guus: suggest briefly review this list, pick out critical issues, spend time discussing critical issues, diego can play a role because has proposed resolution for one of these issues (we can discuss and decide on)
jon: first four issues left over from previous working group, diego's been working on first issue.
Diego's proposed resolution to COOKBOOK-I1.1
diego: [issue 1.1] already on mailing list, there was a TODO tag, issue regards configuration of apache to serve vocabularies, apache uses configuration files with directives, one of these directives is the overrides ...
<JonP> Diego's verification email: http://lists.w3.org/Archives/Public/public-swd-wg/2007Jan/0005.html
diego: in original doc there was a TODO tag
next to overrides, to verify this is correct, I checked
this and discovered that the line was correct, no
additional overrides required, both overrides are
... proposed to remove this TODO tag.
jon: is that resolution acceptable? how do we
handle? seems to be fine.
... vote as a group?
guus: can we write a test case?
diego: I have test case.
jon: diego sent around email, describing test cases and results.
<berrueta> test cases
guus: further discussion?
PROPOSED to resolve issue 1.1 as per email of http://lists.w3.org/Archives/Public/public-swd-wg/2007Jan/0005.html
<scribe> ACTION: jon to update issue list as per resolution of issue 1.1 [recorded in http://www.w3.org/2007/01/22-swd-minutes.html#action10]
jon: skip over second issue, because the TODO
is that it references 6 which doesn't exist
... issue 1.2 and 1.4 are essentially the same.
guus: PROPOSED to drop issue 1.2
RESOLVED to drop issue 1.2
<scribe> ACTION: jon to update issue list as per dropping of 1.2 [recorded in http://www.w3.org/2007/01/22-swd-minutes.html#action11]
jon: issue 1.3 - why performing content
negotiation on the basis of the "user agent" heading.
... is not considered good practice.
bernard: whole section should be in an appendix, why in main body of text?
aliman: karl suggested move whole content negotiation to appendix
timbl: if you add features to a user agent,
because it stumps the deployment of new browsers, e.g.
folks at opera, resulted in user agents lying about who
... e.g. some browsers ship with lying user agent fields, unsatisfactory, better to look at the mime types
... sometimes in practice necessary to look at user agent field to pick up bugs, where you know there are specific bugs, particular trap for particular browser.
jon: potential resolution is to explain the problem with using user agent, as per stunting development?
diego: esiting doc to explain this?
ralph: we didn't want to break semantic web applications which don't include accept header, so set RDF as default response
timbl: two cases, one is your serving data, but if you are trying do the trick of doing either rdf html version, but only put if you are content negotiating ...TAG says something about identity of resourse
aliman: but use 303 so don't have to have same info content
bernard: uncomfortable with hack
jon: real world, applies to IE7?
<timbl> The TAG I think says the same URI may conneg go to different representations ... but they should convey the same information
guus: someone take action to look at IE7
jon: regardless of IE7, should still leave hack in.
aliman: I agree
jon: issue 1.3 is actually to explain why the hack is slightly bad
ralph: new issue would be to look again at the hack
jon: two separate issues
ralph: if IE7 does the wrong thing, leave it, if IE7 does the right thing then drop the hack (except if you have to support a specific ocmmunity)
bernard: I will raise this issue
<scribe> ACTION: bernard to raise new issue re IE6 hack [recorded in http://www.w3.org/2007/01/22-swd-minutes.html#action12]
<scribe> ACTION: diego to look at IE7 accept headers [recorded in http://www.w3.org/2007/01/22-swd-minutes.html#action13]
ralph: test cases?
aliman: just whar's in the document already.
jon: 1.3 issue has been raised.
ralph: I move we conside 1.3 open - there is a TODO that needs to be done, timbl how likely is that TAG write something about use of user agent header?
timbl: may be something already, otherwise need to send email to TAG
ralph: I will own this issue
<scribe> ACTION: ralph propose resolutition to issue 1.3 [recorded in http://www.w3.org/2007/01/22-swd-minutes.html#action14]
jon: move on to issue issue 1.4 ... recipe 6 is not there
bernard: do we need a recipe 6
Alistair: one of the reasons people like slash
namespaces is because the response to a GET is specific to
the requested resource and you can incrementally learn more
with additional GETs
... in recipe 5, if you request RDF you get redirected to a namespace document that describes everything
... recipe 6 was intended to permit serving just a relevant chunk of RDF data
<timbl> see: http://www.w3.org/DesignIssues/LinkedData
TimBL: d2rdf does this ... a SPARQL query can
navigate a graph by recursively pulling in documents
...e.g. d2r server does that virtually, enthusiastic about this group pushing linked data, critical thing about linked data is that when you derefrence linked data you get all arcs in and out then human being can navigate the graph, then also SPARQL query can find all the graphs by pulling in all the relevant docs, not as efficient but good, important to make all the backlinks.
... it's good to remind people to include backlinks; dereferencing a student should give you a pointer back to the class
...minimum spanning graph, RDF molecule
... patrick stickler CBD only arcs out: Concise Bounded Description [Stickler, 2005] ... this is important recipse to include
... proposed workshop for web conference about linked data, didn't have space.
<timbl> The D2R Server generates linked data automatically.
jon: this should be opened, this recipe should be written.
guus: open means we work on it now.
timbl: two separate points to be made, first is the recipe redirects you to a file, but the file is vritual, most web servers are virtual, if you redirect to a SPARQL query, doesn't mean that the SPARQL query is evident in the URI, inside that you use a rewrite rule, give a nice URI to your _part_ then use a rewrite rule to create the SPARQL query, hide the SPARQL query.
jon: useful to say that as part of the recipe, best handled by a service that will handle on the fly.
timbl: important to separate, e.g. FOAF files do it by hand, in some cases there is a lot of hand written stuff, fact that something is genearated automatically may apply to other recipes also.
ralph: we are a deployment group, rewriting nice URIs to query URIs, good to show this to get more deployment.
guus: we are in a position to write a resolution to this section, who can do?
ralph: examples of sparql services we can use?
timbl: geonames? d2r server. one does 303 redirect to URI encoded SPARQL query.
ralph: sounds like some code existed.
jon: two parts to this, first part is data, second part is server configuration. We're looking for a document fragment example and server config.
ralph: wordnet is an obvious choice, but the W3C need to commit to D2R service.
diego: I will own the issue
guus: maybe diego can talk with Ralph about wordnet, nice use case, widely used.
ralph: need to get W3C web servers to support the service, but plausible.
jon: issue 2.1 (QA comments) ... karl raised wordsmithing and structural comments, lots, something for each section, I couldlnt' break out individual issues, I'd like to propose we simply open this, I'll take ownership, I'll implement most of his suggestions and propose as modification to the document.
guus: comments from QA people, we owe them a response. Need to go through each response, say what we did.
jon: Issue 2.1 ... raised by me (wiki lies) recipes are specific to apache server, may be applicable in non-apache environments, do we want to provide general template that describes recipes in general, or say that recipes can be implemented by a script.
bernard: general template is possible?
ralph: is there is one web master would recognise then can look at it. cookbook is very practical, make it simple for server admin to do it, if someone wants to submit recipes for other environments then good.
jon: common principles e.g. redirect based on content negotiation, I don't konw enough about other environments to say how.
ralph: like to encourage others to contribute recipes
jon: suggest we provide a place for people to submit new recipes for other environments
ralph: happy with mailing list for proposed translations.
ivan: wiki? ... esw wiki?
alistair: the diagrams were intended to
provide a schematic overview of the behavior we were trying
... hopefully this would give people enough information to implement in other environments
jon: leave this in a raised state? open it?
ivan: resolution to open wiki page.
ralph: willing to own issue, proposed resolution to create wiki page.
guus: publication schedule, can say we don't think it's a high priority if we think resources are limited.
ralph: should be ok, but may get not good configs
jon: issue 3.1 (raised by me) discussion about
differentiating between versions, one reason we use
redirects to supply most recent snapshot of a
... actualy document.
Alistair: consider Dublin Core; it has a fixed URI that is
redirected to the current version of the vocabulary
... an application may be able to deal with versioned URIs, and access older snapshots of the vocabulary
jon: why not use mod_rewrite instead of
redirects, can use redirects to make version ???
... proposing a complete suggestion for a naming convention for handling this sort of thing in a recipe ...
... link is in extended requirements section of original doc
<timblwanted to say 1) the redirect does
not convey that semantics and so the semantics need sto be
onveyedelsewhere and (b) the redirect is an overhead
... and (c) metadata in URI is covered by the TAG in a new finding and is in general bad
timbl: problem with redirects is twofold, part
is when you redirect, redirect doesn't say anything about
what the relationship between source and target is, doesn't
deliver the smeantics you want, also takes time - overhead
- adding it thourgh overhead is to be avoided if possible.
However to be able to track differences between versions of
an ontology is very useful, on web different translations,
different content types, design issues note about this
... TAG is aware of this but hasn't tackled from RDF point of view, I wrote an ontology: http://www.w3.org/2006/gen/ont.n3
timbl: gen ont if best practices could just
dump the map, some metadata can get from apache, if running
CVS can generate metadata from previous versions if you've
got web CVS. If you've got content negotiation can find out
what all the options are from apache config
... that would be ideal, ideal pattern which nobody does at the moment - don't know if I should ask this group or another to look into this.
... suggest this group push this out.
ralph: I'd like us to consider this as a
candidate requirement for discussion, but not for this
document, because this doc was one of what was expected to
be a collection of docs coming out of SWBPD, several
aspects of VM e.g. how to serve them, versioning,
properties about a vocab e.g. provenance, best practices
for all that. SWBPD imagined there would be other docs to
go along with this, I image this would be part of our work,
Jon's soltuoin is plausible but
... consider this as candidate requirement for other VM work, not to try and solve for this doc (recipes).
jon: ralph is suggestins part of resolution of
this issue is to start another document, and that this part
of recipes should point to that documeent. Currently
recipes punt, lots of different ways to do it, nonbody says
what is best way. Part of utility is to say here is a
recipe, a way to do it, this is a generic enough recipe to
work in enough cases.
... so we should reword this doc?
ralph: shows up on our deliverables page ... "principles for management..." we can point to this document.
guus: propose to leave this issue as raised, go on with recipes without resolving it, indicate that this issue is intended to be resolved by another doc.
Ralph: specifically, our deliverable 3. Principles for Managing an RDF Vocabulary
Alistair: in anticipation of needing to use RDF to describe
the relationship between a dynamic thing and static
snapshots of that thing, I've published net/d4:
d4 may provide a basis for discussion
... also GRDDL seems to be in a similar space; making assertions about the relationship between various documents you might be able to access from a namespace
jon: issue 3.2 (testing) diego has written
some unit tests, useful if we could provide a service for
developers who wanted to utilise cookbook recipes, provide
as a server validation service officially
... this would allow you to specify you wanted to test a particular server against a particular recipe
guus: not an issue with the current doc,
ralph: intermediate step to publish the test cases?
jon: thinking more like RDF validation
service, you point service at URL and say which
... diego has already written the code, we just don't have the service.
ralph: you have test service?
timbl: great idea, presentation suggest that you may get more people who validation than go to the doc, so service could point people out to the doc, start from existing situation and lead people buy the hand to appropriate recipes.
guus: question of timing, has to be synchronised.. From pragmatic view, suggest take an action to look at possibilities and report back, time frames and synchronisation.
ralph: can you commit to hosting?
diego: I can write the code.. .
timbl: can it run in a browser?
diego: runs on server side.
guus: before resolving, do some suggestion on the list about how to realise this.
ralph: I could put this in category of vocabulary mangement validator, then falls into big validator project we have.
timbl: rethink about how to support validators, logically if you're going to validate, you can go so many ways ... top of an iceberg.
guus: open issue, diego is owner, first to propose a timescale.
jon: issue 3.3 raised by diego, mod_rewrite is required for all recipes, but we don't say so.
ralph: and apparently not there by default.
guus: jon is to be issue owner.
ralph: probably worth saying here's what apache config file to go to to cause it to be loaded.
guus: close this dicussion on the recipes,
thanks to all, moved to state where can see progress.
... have to think carefully about status of RDFa, Note? relationship with HTML? also think carefully about time horizon for SKOS recommendation, test cases and implementations worry, can see six months document to go to last call, also need a test suite in place, similar to OWL so tool developers can test stuff. Document itself in good shape, but getting to candidate rec may take more time.
l... to keep to schedule, we need to have test suite stage by the summer.