Chances are if you found this page, you already know an index is that list of words and page numbers in the back of a book that helps you or your readers quickly identify and locate relevant information. If you have done any scholarly research, you are probably intimately familiar with indexes and have likely felt the frustration of bad ones.
This very frustration is what led me to become an indexer. Call it disorganized studying, but while working on my Masters degree, writing paper after paper on various American history topics, I repeatedly “lost” information I read in various books. At one point, said Criminal Text flew across the room and was banished from all further uses. Sure, you can blame the reader (or, in this case, the student). But that won’t sell you book. Like so many readers, I have purchased (or not) reference books based on whether or not I could find certain keywords or topics listing in an index. As a genealogist, I have known the sheer frustration of looking up the fifteenth “John Jones” in a series of undifferentiated locators only to find I have wasted far more time than I care of admit on a text that is generally useless to me. So yes, good indexes matter.
Indexes help readers find information in the text by organizing that information in logical patterns. It is more than a list of words, names, and key phrases, though that usually goes into the final work. A good indexer analyzes the text as written, identifies both the key words and key concepts and crafts that information into a document that is its own finished work. It will take those names and places provide context, so a reader knows exactly what individual you are referencing. A good index will allow a reader to find any key information in a text with only one or two attempts to find it in an index, and will minimize the time and frustration of the reader and bring them into the completed text faster. And isn’t that what every author wants?
The real work of an index isn’t done by software, even Artificial Intelligence (at least, not yet). It still requires a human brain to distill complicated concepts into a single word or phrase that will make sense to the masses, across pages and pages of text, and then to format that information into something that is useable and concise enough for readers, publishers, and authors. Moreover, indexes take time. They are usually one of the last things completed in the publishing process with almost no pre-thought, but to be successful (and to make the book successful) it must still be a thoughtful and deliberate process.
That holds true whether the index is a traditional back-of-the-book index, an index embedded into the text for online publication, a compiled journal index, or more. In the end, an index is all about the organization of information for the use of the reader, which, after all, is who we publish for in the first place. And an angry reader – or student – doesn’t sell books.