If you’re writing nonfiction, and especially if you’re writing an academic book of some sort, an index is usually a must. Beyond the sheer dollars and cents value of helping book buyers to see that your book has what they need, you wrote the book because you thought it would be useful to people. And when it comes to your book’s usefulness, a good index can make all the difference in whether or not a reader is able to find the information s/he really needs. A really good index analyzes words and concepts, and it shows the connections between them, all while distinguishing substantive discussions of those concepts from merely passing mentions. In short, indexing is a work that requires analysis, judgment, and creativity—which is why it can’t be done by a computer.
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