ONLINE PUBLIC-ACCESS CATALOGS (OPACs)
Philip Doty

Many libraries of all kinds have electronic Online Public-Access Catalogs (OPACs), one of the major forms of intellectual technologies that libraries and other information agencies offer their clients. Many, but not all, of these OPACs are Internet/Web-enabled, while others are stand-alone.

Among the major intellectual technologies that information professionals generally provide are (Rubin, 1998, Chapter 6):

1. Classification systems
   
   
2. Controlled vocabularies, including thesauri and the Library of Congress Subject Headings(LCSH) http://lcweb.loc.gov/catdir/cpso/
   
   
3. Library cataloging, especially through the use of Anglo-American Cataloging Rules, which revised its second edition in 1998
   
   
4. Indexing and abstracting
   
   
5. Placing databases of all types in relation to other resources and institutions Library of Congress Subject Headings

These intellectual technologies are important tools in the (inter)mediation that information professionals have traditionally provided and continue to provide (Doty, 1998, pp. 183-184):

• Transactional mediation - providing advice to the client, often in real time and often while both parties are in the same place
  
  
• Gate-keeping or social mediation -identifying and providing reliable, authenticated information
  
  
• Intellectual mediation -organizing and distributing information, often linked to major value-adding activities (see Taylor, 1986)

OPACs may be stand-alone or, more commonly, Internet-accessible, as well as have many different kinds of interfaces, whether developed in-house, developed as part of a vendor's turnkey system, or developed from a (Web) template. OPACs vary widely in what records they display, what fields in the records they display, what fields are searchable, and so on. Further, there are often distinctions made within OPACs between publicly accessible fields and records and those fields and records displayable, searchable, and manipulable by the sponsoring organization's staff. The OPACs that are available through the Internet, including those accessible through the Web, often rely on the Z39.50 information retrieval standard, which, in turn, integrates the MARC record into OPACs.

Catalogs depend upon the use of surrogates of materials, i.e., representations of those materials. These records, often called bibliographic records since book materials were the prototypes for them, are built of constituent parts, often termed fields. The growth of cataloging was largely determined by books, so cataloging and catalogs are quite weak in dealing with journal articles, conference papers, and grey literature, as well as digital material, whether born digital or digitized.

The fields in bibliographic surrogates often include author or editor (statement of responsibility), title, date of production, subject headings, availability for loan, number of pages (if in print), series, physical size (if in print), and other characteristics. If online, these records are built from the bottom up, so to speak, from bits and bytes to characters, words, fields, records, and databases.

Libraries, in particular, rely on standards for cataloging for generating the bibliographic surrogates of collections. Among the most important are the Library of Congress Subject Headings, the Dewey Decimal System (http://www.uk.oclc.org/oclc/fp/index.htm), and the MARC record. At the same time, however, it is vital to remember that cataloging (and, therefore, catalogs, including OPACs) is highly contingent on local circumstances, policies, procedures, and history. Local audiences and collections figure prominently in determining the level and characteristics of descriptive cataloging. Therefore, we should expect that OPACs reveal and cause some tension between local needs and remote needs. They do.

Generally speaking, library catalogs, whether online or not, perform several important tasks. First, they list materials in the collection(s) of the institution(s). They identify the physical or digital locations of those items and provide systematic descriptions of the materials. Lastly, library catalogs bring items with similar characteristics together, e.g., author, title, and subject heading. Thus, OPACs and other catalogs facilitate the finding of known items as well as unknown items. Unfortunately, all catalogs tend to fall prey to what Doty calls the "tyranny of topic" -concentration on the "topic" of a work at the expense of other important characteristics (see, for example, MacMullin & Taylor, 1984). http://www.gslis.utexas.edu/~l38613dw/readings/user.html

It is clear that the concept of adding value to OPACs is one of their great strengths. Harmsen (2000) gives us some specific examples, including many of the most obvious:

• Links to full-text, multimedia, composite documents
  
  
• Links to publishers
  
  
• Links to journal titles, especially Tables of Contents (ToC) as well as full-text versions of papers
  
  
• Ability to ascertain the status of one's own borrower account
  
  
• Ability to order, reserve, recall, and renew materials online
  
  
• Links through subject headings, authors, and publishers, especially professional associations, to similar material.

Among the other values of Harmsen's brief paper is the reminder that Web OPACs surpass proprietary (vendors' turn-key) systems in at least two important ways. The standard Web interface requires no familiarity with an idiosyncratic interface and provides hyperlinks to reach text files as well as databases and other digital artifacts (p. 110). At the same time, however, Web-based OPACs have disadvantages, including lack of a permanent connection and lack of navigational cues. A significant disadvantage is the disjunction of licenses between sites that may unionize their Web-based catalogs.

While there is a very large literature about OPACs, such research has emphasized patterns of use, users' satisfaction, relevance of retrieved items, and user interfaces. There has been little focused research on bibliographic display. This situation is disturbing, especially given the growth of OPACs generally as well as of Web-based OPACs. Cherry (1998) reports on a study of how well OPACs fare when compared to published guidelines for digital display. These guidelines, while far from canonical, rely on empirical work in instructional design, interface design, and bibliographic information.

She and her colleagues used a checklist with 133 questions, each about a feature of a full bibliographic display in an OPAC (see Appendix A, pp. 135-137, and http://www.lita.org/ital/1703_cherry.html). The checklist is organized into four sections:

1. Labels, parts of the bibliographic description provided to the OPAC user
   
   
2. Text, the display of the bibliographic, holdings, location, and circulation status information
   
   
3. Instructional information, e.g., instructions to users and announcements
   
   
4. Screen layout, including identification of the screen, organization of the bibliographic information, spacing, white space, and consistency of presentation.

The findings indicate that OPACs generally and Web-based OPACs (sometimes referred to as WebPACs) scored at about 60% when compared to the published guidelines. Among the comparative weaknesses in both stand-alone and Web-based OPACs were: width of records beyond the recommended 40-60 characters, lack of information about circulation status, misleading labels, and use of special characters and abbreviations. In OPACs alone, the most important problems included use of library jargon and lack of the ability to return to the previous screen. The Web-based catalogs often failed to provide online help and to provide links from author and subject(s) fields in the records.

Cherry concludes by reminding us that, according to the research on interfaces and other topics she cites, users are likely to be more successful if bibliographic displays paid greater heed to the published guidelines for such displays. Not only would users be able to find the information they seek, but they would also be able to use their skills with the interface of one catalog to good effect with another. We must remember, however, that Cherry's paper was written at the beginning of the surge in Web-based catalogs. More important, however, is the fact that there is still too little empirical research into the efficacy of the published guidelines specific to WebPACs.

A good point to conclude with is the reminder by Joe (1999) that OPAC'S can be an obstacle to the use of the institution and to the success of users. Causes of such problems range from lack of so-called computer literacy, preference for the card catalog, and the difficulty of being an infrequent or novice user of the particular system. He approached 189 patrons with an offer of assistance while the clients were at the OPAC monitors/terminals and found that 83 (44%) accepted his offer. Further, many of those who refused expressed warm appreciation at being asked (although we always need to be aware of the possibility of the Hawthorne Effect and the expectancy effect).

Joe encouraged the participants to perform their search(es) themselves, responded to questions, or provided more guidance when clients were attempting complex searches new to them, e.g., subject searches. While there were some variations in study results according to the usual demographic characteristics such as race, gender (although he mistakenly says "sex"), and chronological age, he found that the respondents readily accepted his help and appeared very appreciative of the skills they had gained through interaction with the librarian.

This last point is especially important. With OPACs, as with every other tool and intellectual technology, the information professional always walks a very difficult path between doing too little and too much for the patron. But it is wise to keep one of Joe's concluding remarks in mind: "We do not know how many patrons feel excluded by the computer catalog and rejected by their libraries" (p. 157). While such exclusion is not an excuse for mindless technophobia on our part, it is a good tonic to equally mindless technophoria.

Resources

Baker, Nicholson. (1994.) Discards. The NewYorker, April 4, 1994, 64-86.

Cherry, Joan M. (1998). Bibliographic displays in OPACs and Web catalogs: How well do they comply with display guidelines? Information Technology and Libraries, 17(3), 124-137.

Doty, Philip. (1998). Information technology and education for the information professions. In Loriene Roy & Brooke E. Sheldon (Eds.), Library and information studies education in the United States (pp. 161-198).

Harmsen, Bernd. (2000). Adding value to Web-OPACs. Electronic Library, 18(2), 109-113. Also available on the Web: http://www.emerald-library.com

Joe, Ronald K. (1999). Offering assistance at the OPACs. Reference Librarian, 65, 137-159.

MacMullin, Susan, & Taylor, Robert. (1984). Problem dimensions and information traits. The Information Society, 3(1), 91-111

Rubin, Richard E. (1998). Foundations of library science. New York: Neal-Schuman.

Taylor, Robert. (1986). Value-added processes in information systems. Norwood, NJ: Ablex.