How to Evaluate Your Index

When you create an index for a manual, you need to check the index for the following attributes:

Check the index for the following common problems:

Overloaded primary entries: If you find that a small number of primary entries in your index have a large number of subentries, try to find other labels for some of the subentries. Try to keep the number of subentries to a useful level.
Inadequate subentry labels: If your subentry labels are too cryptic, for example just page numbers, then the reader does not have enough pointers to decide where to go in the book for the required information.
Unbalanced entries across the book: If one or two chapters in the book are heavily represented in the index, then you need to look at the indexing frequency in the other chapters. Also, you might want to look at the overall information design structure of your book, to see if you really need those other chapters.

To check the index for clarity and consistency, perform the following actions:

Ensure that all primary entries are nouns: Look through your index for primary entries that are verbs and adjectives. Replace the verbs and adjectives with nouns or noun phrases.
Clarify the relationship between primary entries and subentries: Make sure that the subentries bear a meaningful relationship to the primary entries.
Correlate primary entries and subentries: Make sure that related subentries are all gathered together under the same primary entries.

6.2.1. Balance and Structure