An index is not a glossary or concordance of all the terms in the document. So while all the terms the author uses will be included in the index, a good indexer also includes the terms the user will be looking for, even if the words don't appear in the text.
Indexing skills Many indexes are written by people who have never been trained in indexing.
The USDA introductory course takes about a year to complete. Locally, the University of Washington Graduate School of Library and Information Science offers some indexing classes, and indexing is included in the technical writing certificate program at Bellevue Community College. Information about educational opportunities, as well as indexing as a career, is available on the ASI Web site . Self-instruction is also an avenue. Nancy Mulvaney's Indexing Books is the textbook used by the USDA course.