How many indexes does a book need? And is there any any benefit to creating separate indexes?
When I wrote a couple of weeks ago with a proposal for how I would index Taiwan Travelogue, a novel by Yáng Shuāng-zǐ and translated by Lin King (Graywolf Press, 2024), I received a reply asking why I was proposing separate indexes. Why not combine all of the entries together?
That is a fair question. In most disciplines, the norm is to write a single index. So why suggest multiple?
I think a key consideration is scope. What is being picked up and how well do the elements fit together? A general index, by definition, contains everything, which is appropriate in most situations. But if the scope for what to index narrows, separating the elements into multiple indexes may be helpful, both as a way to sort entries on behalf of the reader and as a way to communicate that only these elements, and not others, are being indexed.
There can also be occasional situations in which elements don’t fit well together. A classic example is a scripture or ancient sources index. The way that scripture references are written, with chapter and verse numbers, is different than a typical main heading and subheading, and the purpose of a scripture index is different than a subject index. A scripture index points to both discussions and mentions (citations) whereas a subject index is focused on discussions. So both in terms of purpose and readability, it makes sense to keep a scripture index separate.
For another example, I was once asked to create a separate index of Greek terms for a book which was an annotated translation of an early Christian text. There were a lot of Greek terms, gathering them together in a separate index made the list easier to scan, and I imagine the audience for the Greek terms was somewhat different from the audience for the subject index (some overlap in audience, certainly, but I think each index spoke to a different interest). If there is a valid and significant difference in audience or function for different types of material, separate indexes can be helpful.
Bringing this back to Taiwan Travelogue, my original thought was to only index foods and places. With only two elements, it made sense to me to create two separate indexes, to be clear with readers that nothing else was indexed. Separate indexes also meant that each index would be short and easy to scan.
Later, I considered indexing supporting characters (a possible third index), and then later still considered what indexing colonialism, the underlying presence throughout the novel, might look like. Where would colonialism fit in? It doesn’t really make sense to have a separate index for a single concept or array. At this point, combining all the entries together into a single index would probably make the most sense. The more indexes present, the greater the ask on the reader to first find the right index.
So to answer the original question, whether or not I would write multiple indexes for Taiwan Travelogue would depend on the scope of what is being indexed. The narrower the scope, the more likely I am to suggest two or three separate indexes. The broader the scope, the value of multiple indexes is lost, and a single, general index is likely best.
Thank you for the question. I think it can be helpful to weigh the pros and cons of different scenarios, to be prepared when a project like this actually shows up.