Today, the Dewey Decimal Classification is the world's most widely used library classification scheme. We look to the next century with the goal of having the Classification evolve to be the world's most widely used general knowledge organization tool. To realize this vision, efforts are underway to improve the Classification for current and future uses. This paper describes some of the efforts to prepare the DDC for the future, and suggests some uses of the Russian edition as a general knowledge organization tool.

The Dewey Decimal Classification is published in two editions, full and abridged. The latest full print edition, Edition 21, was published in summer 1996 and the latest abridged edition, Abridged Edition 13, was published the following year. Since 1993, the full edition of the Classification has also been published in electronic form. Electronic Dewey, an MS-DOS version of Edition 20, was introduced in 1993 and updated in March 1994. Dewey for Windows, the Microsoft WindowsФ -based CD-ROM version of Edition 21, was released shortly after the publication of Edition 21. An updated disc is issued annually.

We expect to publish the next full edition of the Classification in 2003. We are investigating major updates in computer science and medicine, methods of simplifying number building in literature, additional changes to remove Christian bias in religion, and other updates as needed. We are also considering the deletion of Table 7 (Groups of persons) because notation for the topics in Table 7 is already available in Table 1 or in the schedules.

We do not wait for a new edition to deliver changes to our users. We keep the Classification up-to-date on a continuous basis through several devices: two annual publications, Decimal Classification Additions, Notes and Decisions (DC&) and Dewey for Windows; monthly postings on the Dewey home page (http://www.oclc.org/fp/) of new and changed entries; and biweekly postings of new LC subject headings mapped to candidate DDC numbers.

Later this year, we plan to issue major revisions of the area table for the United Kingdom and South Africa. These changes will appear in DC& on the Dewey home page and in the updated Dewey for Windows database. OCLC Forest Press is considering a biennial publication of the area table that would include these changes and others. In addition to providing an up-to-date resource for Dewey users, the proposed publication might also serve the area notation needs of UDC users, and enjoy general use as a geographic thesaurus.

The new and changed entries that are posted on the Dewey home page on a monthly basis are an example of how Dewey has evolved to meet the needs of our users. We realized after the publication of Edition 21 that annual updates were no longer sufficient to keep pace with knowledge. New and changed entries are posted on the Dewey home page once a month on the first of the month, and are implemented at the Library of Congress upon posting. This process began in July 1997 with the announcement of the new and changed entries for the transfer of Hong Kong from British to Chinese sovereignty. These new and changed entries are cumulated along with other changes, and published once a year in DC& and in the updated database on Dewey for Windows.

We are linking new topics of interest to the DDC using issues of the LC Subject Headings Weekly Lists as a guide. Each week, we download the latest list, select topics of interest, and suggest candidate DDC numbers. We then post the headings and numbers to the Dewey home page on a biweekly basis. This process is a method of linking new topics to Classification and a way to provide classifiers with advice on potential numbers for emerging topics. Examples of recent linked headings include Alien abduction, Blindfold chess, Internet addiction, Nude beaches, Styr River (Ukraine and Belarus), Unicode (Computer character set), Uvs Nuur (Mongolia and Russia), and Web search engines.

Our main vehicle for supporting classifier productivity is the annual electronic version of the DDC, Dewey for Windows. Dewey for Windows contains the latest version of the Dewey database, plus additional features and data not present in the print version of the Classification. I will briefly describe some of the additional data in Dewey for Windows: LC subject headings, an expanded index, and an online book.

Dewey for Windows contains selected LC subject headings statistically mapped from WorldCat (the OCLC Online Union Catalog) and headings mapped directly by the editors. The statistically mapped headings are derived from the LC subject fields and subfields in WorldCat records with LC-assigned Dewey numbers. When we derived the statistical mappings of LC subject headings to Edition 21 numbers, WorldCat did not contain any examples of records classified under the new or changed numbers in the major revisions. Therefore, the editors mapped selected LC subject headings to Edition 21 numbers in the major revisions and entered these into the Dewey database. The Dewey for Windows database also includes selected LC subject headings mapped to DDC numbers that have already been announced on the Dewey home page. Dewey for Windows includes a subscription option for access to the full LC Subject Headings Authority File on the same disc as Dewey for Windows.

The electronic edition of the DDC is not encumbered by the same size limitations as the print edition. We are able to add more terms to the electronic index to improve access to the records. For example, the ecology of grasslands is indexed as "Grasslands-ecology" in the print edition, and additionally as "Grassland ecology" in the electronic edition. With the help of OCLC Research, we have identified the 1000 most frequently used built (synthesized) numbers in WorldCat and have added 90% of these to the Dewey for Windows index, along with over 1500 new index terms. The addition of these numbers to the database helps verification of copy cataloging, and removes the need for classifiers to build the most frequently used synthesized numbers. For example, the following new entries have been added for specific forms, aspects, and periods in Russian literature:

Russian drama

1800-1917891.723

Russian fiction

1800-1917891.733

1917-1945891.734 2

1945-1991891.734 4

Russian literature

history and criticism891.709

Russian poetry

1800-1917891.713

1917-1945891.714 2

1945-1991891.714 4

19th century891.713

Julianne Beall, assistant editor of the DDC, has written Dewey for Windows Guide, an online companion guide to help classifiers use Dewey for Windows effectively. The guide is included on the Dewey for Windows update disc, and is also available in print (Beall 1998).

Editorial work on last two full and abridged editions of Dewey has been done using a UNIX-based flat file database system first developed by Inforonics in the late 1980s for the production of Edition 20, and updated by Inforonics for the production of Edition 21 (Beall 1992). OCLC is developing a new editorial support system based on a relational database model. Among the features of the new system is an authority control module that will permit the linking of Dewey with other thesauri (Mitchell 1997). Each entry in the Relative Index will have an associated authority record that combines elements of the MARC authority (Library of Congress 1993) and classification (Library of Congress 1991) formats. Here is a sample index authority record:

Older persons

en305.26

ten1_0846

ten7_0565

sdfPhone call to AARP, 12/13/94

750 00$aAged$w(DLC)sh#85002087

UFAged

UF Elderly persons

UFOld persons

UFSenior citizens

Of particular interest is the 750 field, which documents the equivalent term ("Aged") in another thesaurus (Library of Congress Subject Headings Authority File, record no. 85-2087) that corresponds to the Relative Index entry "Older persons." The database also supports direct linking of terms from other thesauri to schedule, table, and Manual entries. The same type of record is provided, but it is distinguished from a Relative Index record to allow capture in a separate database index.

In addition to promoting classifier productivity, the extended terminology in the Classification is one of the building blocks for the development of machine-assisted classification routines for selected materials. There are several projects underway at OCLC that address automatic extension of the DDC vocabulary and automatic classification.

The Scorpion project is an effort to index electronic resources using a Dewey database enhanced with SMART retrieval software (Shafer 1997). Documents are run against the database as queries, and the results are presented as a ranked list of Dewey numbers. Preliminary results suggest that text-rich Web pages are better candidates for automatic classification than graphics-rich Web pages.

Two other projects focus on automatic enhancements to the DDC vocabulary to make it more useful in Scorpion and other projects. The Dewey ExTended Concept Trees project matches Relative Index terms to LCSH terms and variants, and imports the additional vocabulary (Vizine-Goetz 1997a, 1997b). WordSmith uses electronic newspapers as the source for new and emerging terminology, then matches the terms to Dewey using computational linguistics association techniques (Godby 1997).

The DDC has great potential as a multilingual switching language. National libraries, national bibliographies, and libraries of every type apply Dewey numbers on a daily basis and share these numbers through a variety of means (including WorldCat). Dewey is used in the national bibliographies of fifty-nine countries: seventeen countries in Africa, thirteen countries in the Americas/Caribbean region, seven countries in Europe², seven countries in the Middle East, and fifteen countries in the Asia-Pacific region (Bell 1997).

OCLC Forest Press is pursuing a vigorous translations program for the Classification and related materials. In the last decade, the Dewey Decimal Classification has been translated into Arabic, French, Italian, Persian, Spanish, and Turkish. New translations are proposed or underway in Arabic, Chinese, French, Greek, Hebrew, Icelandic, Italian, Norwegian, Russian, and Spanish.

I have already described Dewey's availability in electronic form. Most of the recent translations of the DDC have been prepared with database and/or word processing support.

Many of these translations are very close in structure and content to the English-language standard edition on which they are based with minor cultural adaptations. In order for Dewey’s potential as a switching language to be realized, there must be explicit links between the English-language standard editions of Dewey and each translation. Several extensions to the present USMARC Format for Classification Data were approved last year as a result of a Library of Congress proposal based on the recommendations of the IFLA Joint Working Group on a Classification Format (Library of Congress 1996). The extensions accommodate the following data needed to link translations and adaptations of classification systems with their standard editions: multiple source editions, the authorization status of the edition, and the relationship of individual numbers to the primary source. The following is an example of how the MARC classification format could be used to show the correspondence between the latest Spanish edition of Dewey and the English-language standard editions of Dewey on which it is based:

084 8#$addc$bSistema de Clasificaciуn Decimal$c20$d21$ncontains parts of Edition 21 in revised area table for former Soviet Union and Table 6 expansions for North and South American native languages$espa

153 ##$z2$a4771$hEuropa Europa Occidental$hEuropa oriental Rusia$hUcrania$jProvincia de Crimea

686 0#$221

The latest Spanish translation of Dewey is based on Edition 20, but contains parts of Edition 21 such as the revised area table numbers for the former Soviet Union and the Table 6 expansions for North and South American languages. The 084 field documents the primary source edition (Edition 20) and secondary source edition (Edition 21) in subfields c and d respectively, and explains the multiple source editions in a note in subfield n.

The 153 field documents each number in the Spanish edition and its associated caption and hierarchy. In the example above, the 153 field contains Table 2 (subfield z) notation 4771 (subfield a) for Provincia de Crimea (subfield j). The h subfields preceding subfield j contain the captions for the numbers in the upward hierarchy associated with Table 2 notation 4771, i.e, Ucrania (477), Europa oriental Rusia (47), Europa Europa Occidental (4).

The 686 field documents the source of the number in the 153 field if it is not equivalent to the number in the primary source edition. In the example above, the number for Crimea comes from the secondary source edition (Edition 21), not the primary source edition (Edition 20); therefore, the source edition is indicated in subfield 2 of the 686 field.

The Permanent UNIMARC Committee has recently appointed a working group to develop a UNIMARC classification format that will parallel the elements found in the USMARC classification format. This will enable linking between the same classification system represented in either format.

Browsers and Alternative Views

Several libraries and Internet information services have independently adopted the DDC summaries as a way to organize and navigate resources on the World Wide Web. The Dewey home page contains links to some of these systems. A Dewey-based browser has been developed for NetFirst, OCLC's database of Internet-accessible resources (Vizine-Goetz 1997a, 1997b). A follow-up project is beginning in spring 1998 to "translate" the captions in the Dewey summaries and in selected narrower categories into end-user language to make the captions more useful in applications such as Internet browsers.

The Russian National Public Library for Science and Technology expects to complete the Russian translation of Edition 21 in summer 1998. Some libraries such as the European University Library at St. Petersburg already use the Dewey Decimal Classification as their primary system (Zverevitch forthcoming). What are the prospects for the use of the Russian edition in other libraries? Most libraries in the former Soviet Union countries use BBK or UDC. With the availability of the new Russian DDC, some libraries might switch to Dewey as their primary classification system. Other libraries such as the Russian National Public Library for Science and Technology plan take advantage of the translation to search WorldCat by Dewey number and to provide additional subject access points for retrieval in their internal databases. The availability of the DDC summaries in Russian has facilitated the inclusion of the Russian captions in the multilingual Dewey screensaver that is available on the Dewey home page and will be distributed to delegates at the 1998 IFLA Conference in Amsterdam. There are plans to integrate the Russian summaries into Mr. Dui's Topic Finder, a prototype multilingual browser available on the Dewey home page in English, French, and Spanish (Bendig 1997). Because the Russian edition is close in content and structure to the English-language standard edition, it will benefit from the same efforts underway to prepare and promote the DDC as a general knowledge organization tool for the next century.