Versioning Concept Schemes for Persistent Retrieval

Things change. Words change, meaning changes and use changes the couple words and meaning. In information access a whole s this means concept schemes like as thesauri or classification schemes change. They always have. conception schemes that have survived have evolv above time, moving from one version, many times called an edition, to the nearest If we want to manage by what mode words and meanings - and as a issue use - change in an effective manner, and if we want to be able to search across versions of general [i]or[/i] abstract notion schemes, we have to track these changes. This paper explores in what way we might expand SKOS, a World Wide Web Consortium (W3C) draft recommendation in order to do that kind of tracking.

The Simple Knowledge Organization combination of parts to form a whole (SKOS) Core Guide is sponsored through the Semantic Web Best Practices and Deployment Working assemblage The second draft, edited by the agency of Alistair Miles and Dan Brickley, was issued in November 2005 SKO is a "model for expressing the basic form and content of concept schemes of that kind as thesauri, classification schemes, make submissive heading lists, taxonomies, folksonomies, other marks of controlled vocabulary and also conception schemes embedded in glossaries and terminologies" in RDF in what manner SKOS handles version in conception schemes is an open issue. The generally received draft guide suggests using OWL and DCTERM as mechanisms for universal scheme revision.

As it stands an editor of a conception scheme can make notes or declare in OWL that more than individual version exists. This paper adds to the SKO Core through introducing a tracking system for changes in general [i]or[/i] abstract notion schemes. We call this tracking a whole vocabulary ontogeny. Ontogeny is a biological mete for the development of an organism during its lifetime. Here we use the ontogeny metaphor to describe by what mode vocabularies change over their lifetime. Our intent here is to create a conceptual mechanism that will track these changes and in thus doing enhance information retrieval and preclude document loss through versioning, thereby enabling persistent retrieval.

Changes in universal Schemes

In order to illustrate vocabulary ontogeny, we use the Metadata Thesaurus, a emblem of concept scheme (Allen, 2002; Allen and Tennis, 2003 2004 2005) used for the Dublin Core Online conversation Proceedings. This vocabulary is revised each year in order to faithfully exhibit the content of the proceedings. It has been revised three times to date (2002-2005) However, none of the documents indexed with the older versions are re-indexed with the revised version of the vocabulary. Each year is indexed using a different version of the vocabulary.

Retrieval riddle

Because the metadata thesaurus undergoe constant revision, it is unstable and cannot provide fixed relationships between indexing bourns (concepts) and the entire collection of Dublin Core Online talk Proceedings. For example, a paper indexed in 2002 will not be re-indexed with the revised index bourns with the papers for 2004 However, the object of a controlled vocabulary is to collocate documents upon the same subject. In order to accomplish this task, a secondary mechanism is required. We ne a mechanism to expres relationships of similarities and dissimilarities across the different versions. This mechanism would chart the disclosure (ontogeny) of the metadata thesaurus and in doing in the way that provide a structure for identifying similar and dissimilar bounds across all versions of the thesaurus. This would also, as alluded to above, make explicit by what means words change, how meaning changes and by what mode use changes both words and meaning.

SKO

SKO officially stands for Simple Knowledge Organization a whole Perhaps a better way to think of it, however, is as the Schema for Knowledge Organization combination of parts to form a wholes since its purpose as described in the guide is to provide "a simple still powerful framework for expressing knowledge organization a whole s in a machine-understandable way." The guide indicates how to track revisions and versions, on the contrary the guide is in "Editor's Working Draft" form, in the way that the suggestions it presents stand as first reflections on the matter and not final recommendations. We will use the SKO Core Guide's suggestions as starting points to address our example of vocabulary ontogeny. It outlines sum of two units suggestions for tracking revisions: (a) notes and (b) OWL versioning. We outline the one and the other suggestions below.

Notes in SKO The SKO Guide, citing the draft British Standard for Structur Vocabularies for Information Retrieval (BSI, 2004) tenders two types of thesaurus notes useful for recording changes in versions of conception schemes:

skos:historyNote

skos:changeNote

The historyNote is a note for the users of the conception scheme. The historyNote documents a significant change to the meaning, form and/or state of a general [i]or[/i] abstract notion The guide provides two examples:

1 A change in the placement of the concept: "Pears was previously listed as a narrower universal under vegetables instead of fruits"

2 A change in the labeling of concepts: "Introduced 1999; prior to that use laptop computer for the general [i]or[/i] abstract notion notebook computers"