Understanding Book Indexes

One of the elements of a book that doesn’t get spoken of much is the index. An index is essentially a roadmap to the book, listing names, places, and things in alphabetical order and giving the page numbers associated with each topic. For nonfiction books, packed with valuable information, a well-made index can help quickly direct the reader to the information they’re trying to find.

A common misconception is that indexes are crafted primarily by computer systems. The truth is that a high-quality index requires a human touch. Catharyn Martz is a skilled indexer and says that when creating an index, she’s constantly asking herself, “What is the author talking about, what else is the author talking about, and how does it relate to other topics in the book?”

Indexers need to make some judgment calls when building the index, and according to Martz, “Most of all, I need to write an index that the reader can trust.” Here are a few other things she keeps in mind when building an index.

Creating Logical Headings

Placing themselves in the shoes of a reader, indexers try to think of the most logical way a reader would find information. Perhaps the term used by the author in the text has a commonly used synonym. An indexer should ask themselves, Which terms will the reader likely use?

For instance, in a book about finance, the intended audience may be the general public, in which case stocks could be the term they’d likely use. Whereas, if the intended audience is investment professionals, the term equity may be preferred. Indexers will gather information around one heading and make sure that there are appropriate cross-references from similar terms back to that heading.

Considering Concepts

Authors don’t always use specific terminology to make a point. Sometimes they’ll use an example or an anecdote to demonstrate a concept instead. The word itself may be missing from the page, but if the concept is important to the content of the book, it should be included in the index.

Deciding What Stays and What Goes

Not every term or name from a book ends up in an index. So how do indexers decide what to include and what not to? The general rule of thumb, according to Martz, is to distinguish between “important” and “trivial” references to a topic. Would the reader learn anything about this topic by flipping to that page? Is the topic mentioned relevant to the overarching themes of the book? If the reader doesn’t gain anything from the mention, it’s likely to be left out.

Using a Computer Program (Sometimes)

Keeping track of all these terms isn’t easy. So while indexes aren’t created solely by computers, indexers do rely on them to help stay organized. There are several indexing software programs out there, and they function like a database, with fields for the heading, subheading, and page numbers. These programs allow indexers to edit their indexes easily, double check their cross-references, and format the index for publication.

Overall, the art of creating an index relies heavily on the indexer’s ability to get inside the head of the intended reader. The better they do that, the easier the book is to navigate.