Extending bibliographic languages

Until now, it has been observed that the representation capability of Topic Maps of

bibliographic languages covers the flexibility in naming due to the use of the identification mechanisms, the limitation of the referential semantics. It also covers their relational semantics, which can be not only exactly modeled with Topic Maps, but enhanced and extended as well. However, as explained in 3.3. this capability of Topic Maps (to represent bibliographic languages, and specially work languages) is focused on their capacity to extend

relationships, which is cited as the main reason to consider them an “evolution” of existing KOS.

This is because the LIS community had already noticed the need for this extension. Svenonius (2000) for example states that “traditional guidelines for constructing subject languages define related-term relationships vaguely, negatively, and broadly to include all semantic

relationships, except equivalence and hierarchy”, and express clearly that “the breaking down of generic related-term relationships into groups of more specific relationships would seem to be inevitable in the general evolution of subject languages toward specificity and formalism.” (p.160,162). Hjørland (2006) also commented on this necessity of all bibliographic languages to be enriched by term definitions, notes on term usage and the more defined relationships. The Medical Sciences, for example, is one of the domains where explicit near-relatedness associations are an urgent need (Hjørland, 2006). One application where Topic Maps was used for this purpose in this domain is explained in Okada et al. (2007), who used a topic map to display the relations of the words used by medical departments.

Besides near-relatedness associations, hierarchical ones also claim for more explicit

statements: “Most seriously, perhaps, if the different types of hierarchical relationships are not distinguished, any attempt to translate among several classifications or simply to achieve compatibility in retrieval is impaired” (Svenonius, p.165). Bøckman (2007) also found that the vocabularies in the Humanities are fully populated with persons’ names and work names, and those ones are not usually compatible with thesauri (which keep subject terms) in the sense that there is no meaningful way to map them. He presents one example30 stating that it will be a challenge to integrate for example the proper name ‘Abildgaard’ into a thesaurus structure that specifies the NT or BT for period names such as ‘classicism’ and ‘romance’ under the BT ‘modern times’ which has as the same time ‘historical time’ as BT, since

‘Abildgaard’ cannot have NT or BT. In Topic Maps this could be solved easily with the use of

topic types for ‘person’ and an association type named for example ‘belonged to historical

30

The original text is in Danish: “Det er en selvstændig udfordring, som det ses nedenfor, at skulle integrere disse to hovedtyper af emneord i en samlet organisering, primært fordi navne-emneordenes evne til at indgå i fx taksonomiske relationer (BT/NT) er omvendt proportional med deres præcision (periodebetegnelser

period’; or, with the CIDOC terminology, using an association type ‘was born’ which will be linked to artistic and cultural periods in history.

Lewenberger et al. (2006) applied Topic Maps in modeling the Getty Art and Architecture Thesaurus, by dissolving its hierarchical composition into association types that could express the implicit semantic relations.

Equivalent relationships also suffer from this limitation of bibliographic languages in describing relations:

“See references are sometimes used to link antonyms, on the grounds that antonyms represent opposite points on a continuum scale and, thus, really refer to the same concept. However (again), the use of one device for multiple purposes has the potential to cause trouble. In this particular case it has the potential to cause serious miscommunication in retrieval, to deteriorate precision, and to obstruct transparent linking.” (Svenonius 2000, p.159)

In Topic Maps, antonyms would be considered as different topics, related by the association “opposite of”. Besides, through the use of scope, it is possible to explain why a term is non- preferred.

This capability of Topic Maps shows the promising possibilities for the improvement of bibliographic languages. Indeed, thesauri (and ontologies –‘terminological ontologies’) have been considered to be enhanced by using explicit relationships through Topic Maps. Yi (2008) insisted on the need for further developing the capacity of Topic Maps in allowing the expansion of thesauri by making explicit the associative-relatedness relationships. Garshol (2004, p. 386) and Kongsbakk (2004) also describe this idea. Besides, the effect of this “expansion” that Topic Maps make of thesauri has already proved to be useful in retrieval systems by having a positive influence on “improv[ing] recall and making the search time shorter for relationship-based queries than for those of a thesaurus-based information retrieval (TIR) system […] The results of this study attest to the potential of Topic Maps-based

ontology to improve information retrieval system performance through better support for associative relationships between terms belonging to different hierarchies by providing explicit relationships among resources” (Yi, 2008).

Nevertheless, extending bibliographic languages in this sense would appear at a first sight to be costly and difficult to implement: “mapping various types of related term relationships from one controlled vocabulary to another can lead to massive intellectual effort to resolve subtle differences between them” (ANSI/NISO Z39.19-2005). Pharo (2004) has also

manifested the need for research on the mechanisms to implement the associations that are not hierarchical in subject languages.

However, even though the implementation would require additional efforts, these are reduced by the existence of vocabularies that can provide normalized terms for the association types and role types that that could be reused (Sigel, 2006, slide 55). Few examples are:

- There are several languages providing association types: Perreault (1965, as cited in Sigel, 2006) published a classified list of 120 relationships, including proposals from various classification specialists such as Ranganathan; and Schmitz-Esser (1999, as cited in Sigel, 2006) compiled a controlled vocabulary on association types, which was used in the Integrative Cross Language

Ontology (ICLO). The CIDOC/CRM which is inherently defined to provide “definitions and a formal structure for describing the implicit and explicit concepts and relationships used in cultural heritage documentation.”

- Relator codes that already exist could be reused as role types. “The value of this ‘role’ information becomes very apparent in light of FRBR. We need to regain the lost link of relator terms and codes in our bibliographic records” (Tillet, 2003).

- ‘Document types’ could be reused as occurrence roles

Chen and Chen (2001) referred to these enhancements as being a “relationship-centric approach [which] should be highlighted as a key framework for knowledge organization theory”. Topic Maps provides the mechanisms for implementing it.