Changing values in the published literature with time

INTRODUCTION

We've kept stored knowledge like holy relics and fewer people believe

in relics all the time. I once had the pleasure of breaking bread with

Mortimer Adler .. Dan Boorstin had asked him what he thought the

Library of Congress should save, and he replied that the secret was to

burn everything older than fifty years and keep burning as time went

on. So long as you kept the last fifty year's worth of nonfiction--he

excluded belles-lettres--he claimed you'd always have what you needed.

Why? Because every profession carries along what matters in its new

books and junks the myths and the mistakes of the earlier generations.

(Goodrum, 1987, pp. 76-77)

The conventional wisdom that print materials decline in both use and usefulness with age is shared not just by librarians-turned-mystery-writers but also by many researchers and librarians. In the jargon of library and information science, this phenomenon is called obsolescence. This term has traditionally been used to refer to the hypothesis that the pattern of use of print materials over time will show a predictable and observable decline in use with age (Line & Sandison, 1974, p. 283; Stinson & Lancaster, 1987, p. 65; Motylev, 1981).

The body of literature which has tested the obsolescence hypothesis has grown to considerable size over the past several decades, but the pattern of research has seldom deviated from the exploration of a single easily measured criterion--i.e., the number of uses of the items studied. Yet researchers have not reached a consensus about the validity of the obsolescence hypothesis. They have not agreed on the mathematical model that best represents obsolescence (Stinson & Lancaster, 1987; Avramescu, 1979; Motylev, 1981; Egghe & Rao, 1992). When research results have failed to show the expected measurable decline in use, researchers have suggested a variety of mitigating factors (usually contextual variables) that they believe are responsible for skewing results.

The lack of consensus among researchers about fundamental questions related to obsolescence studies suggests that another kind of exploration of the changing uses of print materials over time is needed. What has traditionally been assumed to be evidence of obsolescence in the literature of library and information science may be more productively understood in terms of changing relationships among dynamic populations of users and their uses of printed materials, the population of published materials available, and the period of time under study.

A RATIONALE FOR A NEW APPROACH

The nature of printed books or journals may have much to do with their changing uses over time. Toffler (1970) has noted accurately that few objects have a single easily definable function; printed materials are no exception. Like the elephant encountered by a group of blind men, books or other publications can seem to have different identities depending on the dimension which one chooses to examine. It is proposed here that books, journals, and other published materials have three dimensions. They exist simultaneously: (1) as artifacts of human knowledge production, (2) as conveyors of information, and (3) as recorded statements of an author or authors at a particular point in time.

The first dimension of books or other published materials has to do with their existence as artifacts of human knowledge production. Books have always possessed a cultural significance beyond, and sometimes unrelated to, the information which they contain. Cressy (1986), for example, has documented uses of books in previous centuries as magical talismans, aids to divination, devices for social display, symbols, or totems. The use of books as a visible display which provides evidence of erudition is not unknown in contemporary American society.

The rare book trade is evidence that, along the dimension of artifact, books tend to appreciate with age, assuming a decrease in numbers of similar existing items in usable condition. From this perspective, a publication may be said to be obsolescent when its physical condition deteriorates to the point that it is rendered unusable. At that point, its value as a rare commodity is greatly diminished if not lost completely.

The second dimension of published materials, that of conveyor (or container) of information, is the dimension most frequently examined in the library obsolescence literature and in the literature of particular disciplines. It is a truism that many publications become less frequently used with the passage of time. They "age" or "decay" or "obsolesce," in the language of library and information science researchers, because they contain information that clearly has been superseded by works which sandwich the important parts of previous works between a literature review and some new information. Obsolescence researchers see this side of the print-materials "elephant" when they examine published works. Librarians struggle to make weeding and off-site storage decisions about works because they view them along this dimension. To casual observers, the decline in use of older works superseded by newer ones is sufficient evidence of the validity of the obsolescence hypothesis.