What is an Index in a Book?

While the glossary defines specific words found in a book, the index merely tells you where to find them. As a part of the back matter, the index is found in the end pages of a book, and it can be a resourceful tool for readers who may be using the book in their research, or for readers who just want to read up on a certain subject.

An index is an alphabetized list of subjects and terms used and discussed in the book with their corresponding page numbers and is great to use in nonfiction books. It serves as a key or map for finding specific topics in lengthier books. The words listed can be technical terms, places, persons, or multiple words.

Keep in mind that not every single word used in the book should make it into this list (this would be absurd and make for an impossibly long book). Use only terms or phrases of importance with page numbers that lead to sections where those terms or phrases are explained and discussed thoroughly.

An index is not the same thing as a table of contents. The table of contents (or contents page), which is found in the front matter of a book, lists parts, sections, and chapters of the book and their corresponding page numbers. This is for navigational purposes, just as the index is, but the index has more to do with subjects.

Why Should You Include an Index in Your Book?

Simply put: it’s a good navigational tool for your readers. Perhaps those readers are writing a paper on a certain topic, and they wish to use your book as a reference. It’ll be easy for them to flip to the back, find the subject they’re looking for, and flip to its rightful page number. Imagine how much harder this task would be if they had to thumb through every page in the book until they came across what they were looking for!

Another reason the index is useful is that it provides readers with the ability to decide if they wish to purchase your book in the first place! Say a reader is looking for a book that covers a specific topic – say, the Battle of Bunker Hill. They can grab your book from the shelf, scan the index to see if the Battle of Bunker Hill is listed covered, and decide if your book is the right choice for them.

How the Self-Publisher Can Include an Index 

First things first: be sure the index, just like the glossary, is alphabetized and neat. Readers need to be able to quickly scan the list and find what they’re looking for, so any unnecessary clutter needs to be eradicated.

Before you self-publish your book, you can easily add an index to your back matter. To round-up all the pages a certain topic falls on, search for that word or phrase in your Microsoft Word document. To do this on an Apple computer, press ‘command’ + ‘F.’ To do this on a Windows computer, press ‘control’ + ‘F.’ Once you’ve located all the pages that include this word and discuss it (not just mention it in passing), note those pages in your index.

If you create an easy to read, neat, and concise index, your book will be all the better for it, and your readers will no doubt appreciate your efforts on their behalf. Indexes are great to use in nonfiction books as they assist readers in finding specific sections of the book.