This last section should round out our four-part look at getting a quality index done for your book (see below for a link to the whole series).
Posting different versions of your indexable term or using cross-references to other related terms is very much like the hyperlinking function used to link topics on the Web. And in ebooks, the index (yes, indexes are useful for ebooks) entries themselves directly link to the text.
For a traditional printed book index, double-posting and cross-referencing provide similar alternate methods for finding the information in your book faster (you just flip back through to a page instead of clicking a link. :))
As you are deciding on topics to put in your index, you’ll run into some that are synonymous or closely related to one another. Just keep this concept in mind: don’t make the user go to more places than necessary to find what they’re looking for. The main reasons we have cross-references are to force users to go to our preferred vocabulary and more usually, to send them to entries that have a bunch of subentries and thus save space by not double-posting in both places. So, your first choice is to double-post synonymous terms as main headings with their locators, so if the user goes to either one, they will find what they are looking for. Second choice is to use a cross-reference to steer the user to the main spot in the index where the information will be given, or to provide connections to related topics that are also covered in-depth.
If you can keep these basic principles in mind when creating an index for your readers, you will make it much easier for them to find more detailed topics that they kind of remember from reading, or get a basic idea of what your book is about if they are browsing to buy, or find that discussion they want to cite when they are using your material in their book.
Just ask yourself, “Is this a useful term displayed in a useful way for someone to find what they need in my book?”
As our own courtesy, We’ve have taken this post along with parts I to III and combined them into a PDF (Writer’s Guide to Book Indexing) that you can download to keep as a reference.
And if you are still overwhelmed by the indexing process and would like some pro help, we’re right here (firstname.lastname@example.org).