Presentation on theme: "Using SKOS in practice, with examples from the classification domain"— Presentation transcript:
1 Using SKOS in practice, with examples from the classification domain Antoine IsaacAida SlavicUDC Seminar 2009
2 SKOS Simple Knowledge Organization System SKOS is a model to represent KOSs on in RDF in a simple wayNot aimed at fitting everything!Not aimed at replacing existing (non-web) formats!Now an official W3C recommendation
3 SKOS basis SKOS offers a vocabulary for Concepts and concept schemes LabelsSemantic relationsNotes
4 Networking controlled vocabularies in SKOS Matching properties as conceptual relationsKOS2animalhumanobjectKOS1animalscatswildcats
5 The relevance of networked KOSs Johan Stapel, Koninklijke Bibliotheek, Den Haag
6 Pointers to SKOS deployments SKOS implementation reportLibrary of Congress Subject Headingslcsh.infoRAMEAU subject headingsstitch.cs.vu.nl/rameauDDCdewey.info
8 Representing classes as concepts 21.51 Techniques and materials
9 Relationships between classes 21.50 Sculpture: general21.51 Techniques and materials
10 Issues with SKOS representation of classifications Captions and labelsLanguagesTime versions of classesCoordination of classesAuxiliary elements…
11 Issue 1: notations, captions and labels SKOS enables representing notationsAnd human-readable preferred (or alternative) labels, suited for captions21.51 Techniques and materials
12 Different choices for notations? Can notations be SKOS preferred labels?They make sense for users & can be displayedWe can represent them as language-neutral labelsSeveral choices!
13 Issue 2: Multiple languages SKOS concepts can have labels in various languages
14 Issue 2: Multiple languages On dewey.info: one concept per class & languageSeveral choices!
15 Issue 2: Multiple languages Introducing an abstract entity that denotes the time/language-independent classIn RDF, it is possible to use other models in combination with SKOS…Using Dublin Core's isVersionOf link
16 Raising difficult issues: what is a "concept"? An artifactused in descriptions, e.g., as subjectsused as a cluster for different labels with a similar meaningin semantic relationships with other conceptsbasis for Knowlegde Organization SystemsWhat qualifies as a concept for DDC? For UDC?Can different choices be done?
17 Issue 3: Tracking modifications 2 RELIGION. FAITHS21/28 CHRISTIANITY21 Natural theology. Theodicy. De Deo 22 The Bible. Holy scripture 23 Dogmatic theology 24 Practical theology 25 Pastoral theology 26 Christian church in general 27 General history of the Christian church Christian churches, sects 29 NON CHRISTIAN RELIGIONSNOW.....2 RELIGION. FAITHS 21 Prehistoric and primitive religions 22 Religions of the Far East 23 Religions of the Indian subcontinent 24 Buddhism 25 Religions of antiquity 26 Judaism 27 Christianity 28 Islam 29 Modern spiritual movements
18 Creating representations of the versions Each time-specific version should be a skos:Concept because:They are related to other (versions of) classesClassification act refers to a time-specific versionA book on the Bible would be wrongly classified by "22" if "22" is the notation for "Far Eastern Religions"
19 Representing versions of classes IF WE FOCUS ON NOTATION... 22Representing versions of classesUsing Dublin Core's isReplacedBy link
21 Notations as aggregations Notations can be seen as hubs for time-specific version of classesUsing the aggregates linkfrom Object Reuse & Exchange (ORE) initiative
22 Tracking "Far East religions" in UDC database CLASS ID: 16544NOTATION: 22DESCRIPTION:Religions originating in the Far East*REPLACES: DESCRIPTION: Religion of Oriental peoples ID: 15999NOTATION HISTORY : YES OLD DESCRIPTION: BibleThere is interesting history information (incl. IDs) in the vocabulary management system!
23 Concepts across notations "Far East religions" existed before: 299.5It does not belong to 22 aloneThere is a more abstract Far East Religion entityits conceptual content may be updated while it keeps its position in the hierarchyit might be moved in the notation hierarchy and retain its conceptual content
25 Towards stable abstract concepts? Problem: these "abstract concept" entities are not currently explicit in UDC, there is no ID for them
26 Two different versioning & aggregation mechanisms at work
27 Conclusion SKOS is an interoperability enabler There are still issues Different conversions reveal different choicesBut that's not a new problem, reallyStandardization often needs best practices & use casesNow, it is easier to publish and compare dataAs data is (will be) linked, it is even crucial to do it!Interaction between information experts and techies is crucial
28 Thank you! Questions? Drawing inspiration from Joseph Tennis & Stuart SuttonMichael PanzerJakob Voss