School of Information Management & Systems.
245   Organization of Information in Collections.   Buckland. Spring 2000.

Exercise 4: Thesauri. Due Feb 23.

There are various kinds of indexes that use words, most obviously simply searching for any occurrence of some particular word which represent a topic of interest to you, but may not have been used for that topic by the author; and "controlled" vocabulary systems which invest in establishing and encoding the relationships between related words (such as synonyms). Examples of the latter include lists of subject headings, back-of-book indexes, and thesauri. There is no fundamental difference between a Thesaurus and a list of subject headings, but, generally, thesauri contain only single words or phrases and subject headings are complex composite statements with an internal syntactical structure (e.g. the LCSH heading Ireland -- Folklore -- Congresses), making multiple elements strung together by the indexer (aka "pre-coordinate indexing"). In this exercise you examine some examples.

A thesaurus generally has single terms (or phrases) suitable for a searcher to combine in Boolean searches (aka "post-coordinate indexing"). Usually there is a Scope Note ("SN" = Definition) and the relationships between terms are made quite explicit, generally in the form
USE [= use some other heading] and its reciprocal USE FOR - for synonyms.
e.g. Dowsing USE Divining-rod; Divining Rod UF Dowsing. Usually relates synonyms.
NT = "See also the Narrower Term" and its reciprocal
BT = "See also the Broader Term": Dogs NT Spaniels; Spaniels BT Dogs.
RT = "See also the related term": Birds RT Ornithology. And sometimes
SA = "See also": Dog breeds SA names of specific breeds, e.g. bloodhound, collies,...
Ability testing SA subdivision Ability testing under subjects, e.g. Dentists--Ability testing.

1. Before you start, read David Batty's "WWW --- Wealth, Weariness or Waste: Controlled vocabulary and thesauri in support of online information access" D-Lib Magazine. November 1998.

2. Then go to the American Society of Indexer's website
In the menu top left click on "Resources" -- then on "Online Reference Sources" in the main menu -- then on "online thesauri" at end of the first paragraph. You should reach a page where they have a list of web-accessible thesauri

3. Imagine that you had decided to add your St. Valentine-day cards to an online database of materials that you are assembling in order to write your autobiography. Suppose that you are about to assign the metadata "St. Valentine-day card" as genre and "Courting" as a topical description. Let's make sure you are doing it right by checking a thesaurus of terms related to graphic materials, so click on Thesaurus Thesaurus for Graphic Materials which is in two parts.
TGM I: Subject Terms which has terms for use in describing what is depicted and
TGM II: Genre and Physical Characteristic Terms which has terms for describing the form of material.
Use TGM I and TGM II to find the records for the headings the Library of Congress would use for "St. Valentine-day card" and for "Courting". When you find them, take a quick look at the related and broader terms.

4. Go back to ASI list of online thesauri pick choose any one, look up some terms of interest to yourself, and (very briefly) report on what you found. Add any comments on what you may have learned about thesauri from this exercise.