In the English language, indexes have been referred to as early as 1593, as can be seen from lines in Christopher Marlowe's Hero and Leander of that year:Ī similar reference to indexes is in Shakespeare's lines from Troilus and Cressida (I.3.344), written nine years later:Īnd in such indexes, although small pricks The concept embodied by book indexes lent its name to database indexes, which similarly provide an abridged way to look up information in a larger collection, albeit one for computer use rather than human use. Perhaps the most advanced investigation of problems related to book indexes is made in the development of topic maps, which started as a way of representing the knowledge structures inherent in traditional back-of-the-book indexes.

Internet search engines (such as Google) and full-text searching help provide access to information but are not as selective as an index, as they provide non-relevant links, and may miss relevant information if it is not phrased in exactly the way they expect. In a library catalog the words are authors, titles, subject headings, etc., and the pointers are call numbers. The pointers are typically page numbers, paragraph numbers or section numbers.

The indexer performing the selection may be the author, the editor, or a professional indexer working as a third party.

In a traditional back-of-the-book index, the headings will include names of people, places, events, and concepts selected as being relevant and of interest to a possible reader of the book. An index differs from a word index, or concordance, in focusing on the subject of the text rather than the exact words in a text, and it differs from a table of contents because the index is ordered by subject, regardless of whether it is early or late in the book, while the listed items in a table of contents is placed in the same order as the book. Examples are an index in the back matter of a book and an index that serves as a library catalog. List of words or phrases and associated pointers The first page of the index of Novus Atlas Sinensis by Martino Martini, an altas of China published in 1655Īn index ( pl.: usually indexes, more rarely indices) is a list of words or phrases ('headings') and associated pointers ('locators') to where useful material relating to that heading can be found in a document or collection of documents.

Indexes