Why does a nonfiction book need an index?

• Providing an index for your book shows that you value the needs of your readers and believe in the importance of providing easy access to the information buried within the pages. Try to think of an index as a map to the concepts, topics, and names you have so carefully written about.
• A good index provides access to information using different terminology than what you may have used in the book. For example: an author discusses zoology in her book. In addition to creating an index heading for “Zoology,” the indexer might also create the heading “animals, study of,” with either the same page numbers (called double posting), or with a cross-reference: “see” Indexers are experts in figuring out the different words and phrases someone will use to find what they’re looking for.
• A good index will break down large chunks of information, often spanning many pages, into subheadings. This makes it easier for the reader to find what she’s looking for without having to read everything in the broader topic.
• Print indexes and eBook indexes help potential readers (and librarians and professors) decide whether or not to purchase your book. If a book doesn’t have an index, there’s a good chance that a different book will be purchased. Have you ever used the “Look Inside” feature on Amazon? Potential book purchasers use it all the time to evaluate which books to buy, and a book with an index will almost always fare better than one without.

Why do we need an embedded index for our eBooks? Aren’t the search function and print index enough?

• There are different terms for eBook indexes. Linked index, dynamic index, live index, digital index, and embedded index—these terms all refer to an index that has terms or page numbers that can be clicked on to take you directly to the location in the book for that information.
• Although the search function is useful, it can’t take the place of a well-crafted, dynamic index. The index will provide cross-references to related topics, and break down information into subheadings. In addition, the search function will not find information using different terminology. For example, a fitness book may have a section on running. If the reader enters “jogging” into the search bar, it’s quite possible that no results will be found because the author never used the term “jogging.” Indexers are experts at putting themselves in the readers’ shoes, and understanding how they’ll search for information.
• As far as the print index is concerned, static (i.e. not hyperlinked) page numbers are not helpful in Kindles, Nooks, iPads, etc., as navigation to find the pages is slow and cumbersome. In a dynamic index, the user clicks on the page number, and is taken directly to the paragraph where the information is contained, or to the beginning of the page range. Talk about accessibility!
• The other important benefit of an embedded index is related to changes and future editions of the book. In an eBook index the text contains the tags that link the index terms to the place in the text where that information is located. If the book needs revisions down the road, or a future edition is published, those tags move along with the text, so the index links will still be accurate. So, no need to have a new index created from scratch—if material is deleted, the index markers are deleted along with it, and only added material needs to be indexed.

Many authors create their own indexes… why is it better to hire a professional indexer?

• The biggest consideration here is the quality of the resulting index. Most authors don’t have the training or the specialized software to create a quality, professional index. Aside from this, a professionally trained indexer will look at the material with a fresh perspective and with an unbiased eye, and can determine what the users will be looking for and what terminology they’ll be using. Authors should not proofread their own material, why should they be expected to write the index?
• The indexing process will likely take an author much longer than it would an experienced indexer. Would this time be better spent on publicity and marketing … or even working on the next book?

Can a computer generate the index?

• A computer will create a concordance, which is a far cry from an index. A concordance is just a list of words in the book, along with their page numbers. An indexer will point out relationships between concepts and also create entries (headings and subheadings) using alternate terminology that may not be used in the book. Page ranges and relevant subentries will point to, and break down, large or widespread chunks of information. A computer-generated index or concordance can’t do any of these things, and will be more frustrating than helpful to your reader.

How much will this cost?

• This will vary from indexer to indexer, but it depends even more on the content itself. Most indexers charge a per-indexable-page rate. An indexable page is any page containing information that might belong in the index. This generally excludes front matter and back matter, and of course, blank pages. Factors that will affect the price include word count per page, density of information, and the level of detail desired.
• Most indexers will ask for a sample of pages—perhaps a chapter or two from the book—in order to quote a price.
• Additional charges are usually applied for rush work, but that varies according to the individual indexer.

The bottom line: The investment of a well-crafted, dynamic index adds considerable value to the product.