Types of Indexes
The most common type of index is the subject, or general, index. A subject index covers all pertinent information within the book (to the extent allowed by space limits). Like the table of contents, the index is a “road map” to the book’s contents, but is more comprehensive and detailed. A subject index can include specific terms, names, events, as well as more general thematic concepts. A good index directs the user to the appropriate heading with the use of See and See also references (cross-references). In most cases, the index is arranged alphabetically. In some cases, the page numbers (“page locators”) may be distinguished in some special way (for example, italic for illustrations, or bold for main discussion of a topic). Major headings, representing major concepts or themes in the book, may be broken down into subheadings, just as a major folder in a file drawer may be subdivided into more specific minor folders.
Books in the social sciences, which include many research citations, often contain name, or author indexes. A name index includes all names of persons or institutions whose research is cited. The format for headings in the name index is usually “last name, first initial.” Subheadings are uncommon in name indexes. In books with both name and subject indexes, the subject index may also include names when individuals are quoted or discussed at some length.
Cookbooks often include separate subject and recipe indexes. The subject index in a cookbook will include specific discussions or mentions of ingredients and techniques, whereas the recipe index will include all recipe titles, as well as recipes subdivided by specific ingredient. Recipe indexes follow their own specific style.
Periodical indexes are for publications which are released and/or updated at regular intervals, whether a journal or reference work. Periodical indexes often require the development of a controlled vocabulary, or thesaurus, so that the heading terms are consistent as the index is expanded.