In August 2012 I was eagerly awaiting publication of my first research methods book, Research and Evaluation for Busy Students and Practitioners: A Time-Saving Guide (now in its second edition). I received an email asking me to check and give feedback on the attached draft index. I had absolutely no clue how to check an index. It looked like a credible index to me so I sent an email back saying thanks, it looks great, and hoped that would pass muster.

In May 2014 I was delighted to receive another email telling me that the book had been positively reviewed in the International Journal of Social Research Methodology. Although the review was indeed predominantly positive, the reviewer – as reviewers will – offered some criticism too. For example, she stated that, in contradiction to the book’s title, evaluation had only been mentioned once in its pages. Almost two years had passed since I’d worked on the manuscript and I began to doubt myself so I turned to my copy to check. I was reassured to find evaluation mentioned on many pages. But then I wondered, how could the reviewer have made such an error? The rest of her review suggested that she had read the book quite carefully. I turned to the index – and found that there was only one page number given for ‘evaluation’.

I could argue here that the reviewer should have been more careful, or that the indexer should have been more thorough. But actually I think it’s my fault because I didn’t know how to check an index. On the plus side, this is a useful cautionary tale which demonstrates that indexes are used by many people in many ways. This is something that indexers understand, though they are not infallible and will never know a book as well as its author – which is why authors are asked to check indexes. But nobody ever explains how to check an index. So I’m going to try to do just that. I’m still no expert, but I have learned some points I can share.

There are three key points to consider: what the index does for the book, what the index does for the book’s readers, and whether the index is a good index by the standards of other indexes. These can be converted into three questions:

1. Does the index accurately reflect the content of the book?
2. Does it do so in a way that will make sense to your readers?
3. Is the index, in itself, a good quality index?

To answer the first question, begin by making a list of key words from your title, chapter headings, and sub-headings. Ensure all of those words are properly and fully represented in the index. If they’re not, don’t try to fix it yourself or even make suggestions about how to fix the problem. Simply explain to the indexer which words need more prominence and why. Then let them sort it out because they will be able to do so far more quickly and effectively than you.

Once you’ve done that, read through the index with your book’s readers in mind. Is the language of the index closely aligned with the language of the book? Are the headings and sub-headings concise and useful? Is the index logically organised and easy to read? Are there double postings when necessary, e.g. ‘data: quantitative’ and ‘quantitative data’? Is the punctuation clear and consistent?

Then consider the more detailed indicators of index quality, usefully set out by the American Society for Indexing. For example:

• Do main headings or sub-headings have more than 5-7 page numbers attached? If so, they may need to be broken down further.
• Are there a reasonable number of sub-headings for each main heading? If there are more than a column’s worth then some may need to be combined.
• Are sub-headings at a sensible level? If not, revision may be needed.
• Are the page numbers accurate? Spot-check some to make sure.

If you want to know more, the ASI have also produced a book on the subject: Indexing for Editors and Authors: A Practical Guide to Understanding Indexes. I haven’t read it myself yet but it looks comprehensive and useful. (Thanks to Nicola King aka @icemaiden1964 for pointing me to these resources on Twitter.)

When my second edition index arrived and evaluation still didn’t have a high profile, I asked the indexer to make appropriate amendments. Which she did, quickly and cheerfully.

These days I feel more confident when I receive an index to check. I hope you will too.

If you have any good index-related stories to tell, please share them in the comments.

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