Good Indexing

A Profession in which Good Workers Can’t be Replaced with Technology
If you have ever repeatedly thumbed through an index in frustration, trying and failing to find the correct page number for an important passage which you forgot to plaster with a sticky note, highlight, or dog ear, then you know the value and importance of having a good guide in the back of a nonfiction book.

Many books have machine-generated indexes.
Computer software can make lists of general terms and page numbers, but a skilled human is necessary in order to create a detailed and well-written index, enabling readers to quickly find the information they are seeking.

Reference
So You’d Like to be an Indexer
http://www.asindexing.org/i4a/pages/index.cfm?pageid=3316