OCLC research takes experience in classification to the Internet

OCLC researchers have had a long-standing interest in classification practice and theory. When Forest Press became a division of OCLC in 1988, research staff members began working on automated classifier-assistance tools based on the electronic version of the Dewey Decimal Classification (DDC). Electronic Dewey and Dewey for Windows are products that resulted from that effort.

More recently, in 1998, research staff assisted Forest Press in the preparation of the second edition of the publication, Subject Headings for Children (a list of subject headings used by the Library of Congress with Dewey numbers added). These seemingly diverse projects have several goals in common and stem from a common vision for the future of the DDC developed and shared by DDC editorial staff members and OCLC researchers. In the 1995 edition of the Annual Review of OCLC Research, Joan Mitchell, editor in chief of the Dewey Decimal Classification, and I outlined five promising research areas for enhancing the usefulness of the DDC as an online organizing tool: developing customizable views of the DDC, enhancing links to other thesauri, improving links to other editions, transforming the captions into end-user language, and decomposing numbers and using the parts for improved access.

Significant advances, which will benefit CORC users, have been made in several of these areas. For example, in a current prototype of a Web interface to the DDC for classifying users, researchers have designed a number of options to enable users to customize the display of DDC hierarchies, notes and associated terminology.

A great deal of progress has also been made in the second research area, enhancing links between the DDC and other thesauri. Much of this research has been concentrated on linking subject-heading systems like Library of Congress Subject Headings (regular LCSH and LC Children’s headings) with the DDC for the purpose of expanding the vocabulary and terminology associated with DDC classes. Expanding the DDC vocabulary with other subject vocabularies has several benefits. New topics can be rapidly linked to the DDC framework--such as the LC subject headings Aromatherapy for children, Dress codes in the workplace, Dublin Core, Electronic dissertations, iMac (Computer) and Virtual corporations, which have all been recently linked to Dewey. Enriching the DDC with additional subject terminology also greatly enhances its potential for retrieval as well as its use in semi-automatic or automatic classification routines, such as the auto-class feature of CORC (Scorpion). Likewise, the LCSH terms associated with Dewey classes have great potential for assisting users in assigning subject elements during metadata creation.

The third area where significant progress has been made is the revision of DDC captions into end-user language. In a recently completed study, 1,848 DDC captions were reviewed and revised to test the ability of library school students to navigate the DDC summaries to find Internet resources on a wide variety of topics. The study resulted in a number of recommendations for improving end-user understanding of DDC captions and some prototype displays of a restructured DDC. Figure 1 is an excerpt from one of the topic plus subtopic displays.

End-user displays of DDC captions might be used in CORC for pathfinder headings and to support subject browsing of CORC resources. --Diane Vizine-Goetz is research scientist, OCLC Office of Research.