Aitchison, J., & Clarke, S.D. (2004). The thesaurus: A historical viewpoint, with a look to the future. Cataloging & Classification Quarterly 37(3/4):5-21.I

This article gives the reader a history of four decades worth of thesauri experiment and development, beginning in the 1800s with a definition of thesaurus that reads, "a treasury or storehouse of knowledge." The first thesaurus the authors mention by name was the non-alphabetically arranged "Thesaurus of English Words and Phrases." I think that what the authors refer to as a thesaurus in modern times is really a stand in for controlled vocabulary, subject terms, etc. They give an ISO definition that highlights this view: "the vocabulary of a controlled indexing language."

An example of another type of early thesaurus is closely aligned with my idea of a thesaurus coming into this reading: uniterms. Uniterms were one word thesauri, but they didn't last long for obvious reasons. Think about thermal insulation versus electric insulation. In a uniterm thesaurus these very different ideas would both be expressed by insulation. The frequent occurrence of different meanings for words in different contexts led to the extinction of this type of thesaurus.

Tags are used in thesauri to distinguish various categories of entries. Frequently used tags are use, use for, (UF) broader term (BT), narrower term (NT), and related term (RT).

Most thesauri have an alphabetical listing, although it is often paired with another classification scheme such as the Medical School Subject Heading's (MeSH) tree structures. These structures are hierarchies arranged within broad categories and sub-categories that allow for a fuller search in shorter time. The alphabetical section serves as a sort of index to these tree structures, although it does include its own synonyms and related term entries.

Another type of classification scheme is the facets scheme that was first introduced by S.R. Ranganathan of India. His ideas caught on in the UK in the 1940s and 50s and led to the creation of the Classification Research Group (CRG). This group further detailed standards for the faceted classification scheme, which resulted in the "Thesaurofacet". This thesaurus combined alphabetical and faceted schemes to form a whole, integrated system. Another example of a faceted thesaurus is the "UNESCO Thesaurus". The "UNESCO Thesaurus" used subject fields/disciplines as its main subdivision. Other faceted thesauri use fundamental categories like entities, actions, space, and time. This form of fundamental categorization was part of Ranganathan's original thesaurus scheme.

Sine the rise of personal computer technology, controlled vocabulary use has left the hands of professionals and traveled to the world of intuitive end-users. The everyman. There are many problems that have since arisen, most notably that different search engines, databases, etc. use different vocabularies and most end-users are not well versed in the lingo. Another problem is that there are so many authors, web-masters, self-publishers that quality control is impossible to account for. So how can the creators of thesauri explain their schemes to end-users? The answer is, unfortunately, not very easily. Most end-users expect a seamless and simple method of search and this most frequently takes the form of keyword boxes where vocabularies of search are hidden behind the scenes.

Two ways to solve this problem are being explored. The first, to create more intuitive vocabularies has frequently taken the form of browsing models like Yahoo. They are simple, classified directories with established headings. The term taxonomy has been applied to these browsing models. It is often corporations that create these models, thus the schemes are not available for public view. This lack of education for the end-user may not be a sustainable method.

Another solution is interoperability, or the ideal of a universal vocabulary across platforms and systems. Here I think of problems searching across databases; EBSCO versus Wilson Web. They may have the same article but describe it under different categories. Mapping is key to this solution, and is a very difficult thing to account for as indexers cannot predict the use or location of every article, category, and idea.

I was intrigued to read this article, mostly because thesaurus sounds like some kind of wonderful dinosaur, and in my head I thought it was-in book form. Turns out thesauri are crucial for indexing and database searching not just looking up synonyms, and I just never realized that there was one for every system, much like there is a catalog for every library and a MaRC record for every entry into that catalog. I wish the article included some example pages of thesauri as some sort of illustration, especially of tree and facet structures, would have been extremely enlightening.