Consistency is key in the quest to provide a smooth user experience. How the index works should be largely invisible to the reader. What we do not want is the reader to find errors or inconsistencies which cause them to question whether their interpretation of the index is correct or whether they are finding everything that should be available. 

In this post, I am going to write about internal consistency, which is making sure that the index is internally consistent with itself. Imposing consistency begins at the start of the indexing process, with selecting which formatting conventions to use and making initial decisions about what kinds of entries to capture. It then continues to be applied during the editing phase, when decisions are reaffirmed and double checked. 

Wording

Consistent wording is a subtle way to add consistency. This is part of gently shaping the reader’s expectations around preferred terms and how to recognize similar information.

If two or more synonymous terms are available, pick one as a preferred term and use it consistently, with a cross-reference if necessary. For a recent book I indexed on the annual encampments of the American Canoe Association, I choose to consistently use the word “meet” for each individual encampment, as in Jessup’s Neck meet and Grindstone Island meets. I could have chosen the terms “camp” or “encampment” instead, which were also used in the text, but I thought meet gave a better sense of community (an important theme in the book), it was short, and by using the same term I hoped to indicate to readers that these dozen or more entries throughout the index were all the same kind of thing. If I had also used the term camp, as in Jessup’s Neck camp, I was concerned that some readers might have questioned how a camp was different from a meet. 

Consistent wording can also be used in subheadings to indicate similar content. Using the same subheading across several entries, as such “accommodation” in a guidebook, indicates to the reader that the same kind of information is provided for all of the locations discussed. Within a single entry, similar wording can gather subheadings so that the reader can easily see all of the related information. For example,

Los Angeles: population growth; population projection

Glosses

A variation on consistent wording is being consistent with glosses. An index can have glosses for different types of entries. Within each type, though, try to provide the same information in the same order. Otherwise, I think inconsistency is visually disruptive and can cause the reader to spend too much time rereading entries to make sure it says what they think it says. For example, the following is not a good idea. Pick a style and stick to it.

Henry VIII (king of England)

James II of England

Louis VI (French king)

Louis XIV (king of France)

Victoria, Queen

Locators

Another basic place to impose consistency is with locators. Are ranges consistently identical, if used at all? Are typographical elements, such as bold or italics, used consistently to indicate figures, tables, or other illustrations?

Treatment of Topics

The last area I will discuss is the treatment of main headings and topics. Consistency here can happen in a couple of different ways. The first is to make sure that all examples of a certain type of information is picked up. To give a simple example, if I decide to index dog breeds, then I should make sure to pick up all breeds mentioned, so that the reader is not wondering, “I see the entry for Dalmatians, but what about Labradors? I am certain I saw Labradors mentioned in the book.”

Another way to be consistent is to treat similar topics similarly. If I decide that some supermain headings should have subheadings to indicate their importance and to break down a longer range, then ideally all supermain headings should have subheadings, even if some ranges are shorter. This is not always possible, if a topic is important but only discussed on 2-3 pages. But I think that consistent treatment is important, when possible, to help the reader identify similar topics and relative importance. 

These are the main areas for internal consistency that I think about when indexing. This can appear to be nit-picky, but I do think that it is the small details that can elevate an index and make for an easier user experience, without the user necessarily knowing why it is a nicer experience. When you index, what areas of internal consistency do you pay attention to? Feel free to reply and let me know. I am curious to know what other areas we should pay attention to.