Years ago I took a class in publishing, and we had a guest lecturer: a professional indexer. It was a fascinating class, because he helped us to see the real craft that goes into making an index — any index. First off, the index needs to suit the book — a nonfiction chapter book that gives a single page to an index printed in large type with lots of leading (space between lines) obviously needs to be created by different rules than a 4 page (thus 8 side) index in small type with many subentries and cross references. This is not just a matter of space — though coming so late in the book-making process, the index is indeed the prisoner of space (sometimes an index needs to be stretched to fit the procrustian bed of the blank pages at the end, other times it is cramped into double columns for the opposite reason)– but of conception. An index has to obey its own rules — is it a list of names and the pages on which they appear? Then you cannot randomly also index one theme, idea, or issue. A book on Cowboys that only lists the cowpokes cannot also have an entry for “ranching,” or “lonesome cowboy songs,” or “movies about.” There must be an architecture of thought — a structure of inclusion, exclusion, and cross-reference — that underlies the index. No reader sh0uld be directly aware of this invisible inner grid, but its firm beams should be felt — you the reader should feel the index is a clear, solid, user-friendly guide whose assumptions you immediately “get” without thinking about them — because that inner invisible frame will guide how you use it.
The problem is that to create a really good index you need to know the book and be a real pro — a person with experience making those inner rules or who is comfortable asking the editor/author about which rules they want applied. I mention this because I used to work closely with indexers — seeing drafts, seeing different assumptions tried out, having to rule on arcane even Talmudic questions of what is a concept, what an idea, what a theme — to determine how an entry should be crafted, or cut. More recently though I have seen indices that betray logic — full of stuff, but without any recognizable hierarchy of inclusion or exclusion; or, indices which use terms at odds with the tone and interests of the book. For example, (this is hypothetical, but makes the point) if the author was very careful about language in a book — you would not expect the index to be sloppy. So if the book were about the indigenous peoples of North America in 1491 and the author carefully named each nation and subgroup, you would not expect the index to say Indians, or Tribes. And yet I have seen similar errors.
I think the problem is that computers make it easy to craft something called an index, and — this is a guess — as a cost saving publishers may find someone who presses the basic computer keystroke, and then is asked to review and massage the printout. I am all for using technology, but this is the opposite of the approach I described above — the pro who crafts an invisible lattice to match both the intellectual structure of a book and the expectations and needs of its readers. A really good index is the publisher’s (editor’s,author’s) final blessing on a book — it is the last, and least calling-attention-to-itself, sign of the craft and attention that has gone into creating a book. But as we know from folklore — it is the mouse that can save the lion — that nearly invisible gift at the very end of the book that opens its pages to readers. Lets hear it for the index, the cinderella of bookmaking, who deserves her turn at the ball.