A library is intended to be a place of organized knowledge. Knowledge organization (KO) takes place in two areas: the shelf and the catalog. In this post I want to address KO in the catalog.
KO in the catalog makes use of "headings". Headings are catalog entry points, such as the title of a work or the name of an author. Library catalogs also assign topical headings to their holdings.
The "knowledge organization" of the title and author headings consists of alternate versions of those. Alternate forms can be from an unused form (Cornwell, David John Moore) to the used one (Le Carré, John). They can also refer from one form that a searcher may use (Twain, Mark) to a related name that is also to be found in the catalog (Snodgrass, Quintus Curtius).
Subject headings are a bit more complex because they also have the taxonomic relationships of broader and narrower concepts. So a broader term (Cooking) can link to a narrower term (Desserts) in the same topic area. Subject headings also have alternate terms and related terms.
The way that this KO is intended to work is that each heading and reference is entered into the catalog in alphabetical order where the user will encounter them during a search.
Cornwell, David John Moore
see: Le Carré, John
see also: Snodgrass, Quintus Curtius
see narrower: Desserts
see narrower: Frying
see narrower: Menus
It may seem obvious but it is still important to note that this entire system is designed around an alphabetical browse of strings of text. The user was alerted to the alternate terms and the topical structure during the browse of cards in the card catalog, where the alternate and taxonomic entries were recorded for the user to see. Any "switching" from one term to another was done by the user herself who had to walk over to another catalog drawer and look up the term, if she so chose. The KO that existed in the catalog was evident to the user.
A database of data creates the ability to search rather than browse. A database search plucks precise elements from storage in response to a query and delivers them to the questioner. The "random access" of that technology has all but eliminated the need to find information through alphabetical order. Before the database there was no retrieval in the sense that we mean today, retrieval where a user is given a finite set of results without intermediate steps on their part. Instead, yesterday's catalog users moved around in an unlimited storehouse of relevant and non-relevant materials from which they had to make choices.
In the database environment, the user does not see the KO that may be provided. Even if the system does some term-switching from unused to used terms, the searcher is given the result of a process that is not transparent. Someone searching on "Cornwell, David" will receive results for the name "John Le Carré" but no explanation of why that is the case. Less likely is that a search on "Twain, Mark" will lead the searcher to the works that Twain wrote under the additional alias of "Snodgrass, Quintus Curtius" or that the search on "Cooking" will inform the user that there is a narrower heading for "Menus." A precise retrieval provides no context for the result, and context is what knowledge organization is all about.
Answering a question is not a conversation. The card catalog engaged the user in at least a modicum of conversation as it suggested entry headings other than the ones being browsed. It is even plausible that some learning took place as the user was guided from one place in the list to another. None of that is intended or provided with the database search.
KW is especially not KO
The loss of KO is exacerbated with keyword searching. While one might be able to link a reference to a single-word topic or to a particular phrase, such as "cookery" to "cooking," individual words that can appear anywhere in a heading are even further removed from any informational context. A word like "solar" ("solar oscillations", "solar cars", "orbiting solar observatories") or "management" ("wildlife management", "time management", "library catalog management") is virtually useless on its own, and the items retrieved will be from significantly different topic areas.
Keyword searching is very popular because, as one computer science student once told me, "I always get something." The controversy today over mis-information is around the fact that "something" is a context-free deliverable. In libraries, keyword searching helps users retrieve items with complex headings, but the resulting resources may be so different one from the other that the the retrieved set resembles a random selection from the catalog. Note, too, that even the sophisticated search engines are unable to inform their users that broader and narrower topics exist, nor can they translate from words to topics. Words are tools to express knowledge, but keywords are only fragments of knowledge.
21st Century Goals
I would like to suggest a goal for 21st century librarians, and that is a return to knowledge organization. I don't know how it can be done, but it is essential to provide this as a service to library users who are poorly served by the contextless searches in today's library catalogs. To accomplish this with computer and database technology will probably not make use of the technique of heading assignment of the card catalog. Users might enter the library through a topic map of some type, perhaps. I really don't know. I do know that educating users will be a big hurdle; the facility of typing a few words and getting "something" will be hard to overcome in a world where quick bits of information are not only the norm but all that some generations have ever known. A knowledge system has to be demonstrably better, and that's a tall order.