Online Public Access Catalog (OPAC)

What is it? 

OPAC was the first portion of ILS to be made visible to the public. During the mid-1980s, libraries began augmenting their card catalogs with a computer system that carried out the tasks of a card catalog and much more. OPAC could also connect users to interlibrary loans, thereby expanding the collection of one library with another. OPAC was able to use data from the MARC catalog to display title, author, and subject. The introduction of OPAC in public libraries was the general public’s exposure to MARC as it translated MARC data in a manner that made its data accessible. OPACs are able to deal with aspects of the “vocabulary problem” by providing suggested topics (much like the “see” and “see also” comments in the old cards and unlike the card catalog), can be searched by keywords.

How is it used by libraries? 

They seem to have supplanted card catalogs in libraries entirely, plus the emergence of protocol has given OPACs the ability to search the catalogs of other libraries or other academic institutions’ collections. There are many commercially available variations of OPAC that are more suitable for different regions or different categories of users like SIRSE/DYNEX (so wonderfully illustrated in Macrovision for IRLS 571 students), TALIS (in the UK), Endeavor, Exlibris, OLIB, InnOPAC, Virtua and others. In academic libraries OPACs can be used to reserve course materials for instructors and can be organized by classes or instructors.

What is the expected social impact of this technology?

In the Butterfield reading for this class, there is mention development in the direction of web-based OPACs and wireless public access catalogs, and already we have the ability to search library catalogs online from our homes, negating a trip to the library until we are certain they have the books we want in the stacks. However, the “online” in the original definition of OPACs, is what would now be classified as an intranet or VPN in modern parlance. In fact in researching for this essay, I naturally looked at the bastion of truthiness, Wikipedia, which has a whole subject heading about the decline and stagnation of OPACs (http://en.wikipedia.org/wiki/OPAC#Stagnation_and_dissatisfaction)

But I think the stagnation and dissatisfaction are about the earlier, “purer” versions of OPAC which pales in comparison with the tricks and capabilities that can be rendered with a modern web search engine, which has such features as ranking hits by relevance to the query and uses histories of similar searches in an effort to weed out irrelevant hits. Once the technology of commercial search engines is combined with OPACs, libraries are going to get another boost as patrons will have a lot more health in tracking down books on the subjects they are interested in. The online catalog at the UA library seems to have some features in line with a commercial search engine, it seems to rank titles by relevance when searching by subject.