An index, while never the glamorous part of any writing project, is essential to the readability and usability of longer non-fiction and technical works. Building one need not be a chore, but it should not be an afterthought either. Here’s how to make an index useful to readers without it becoming an unduly large project:-

1. Understand the purpose of an index. An index is an alphabetical listing of key words and concepts in the text. It contains “pointers” to those words and concepts, which are usually page, section, or paragraph numbers. An index generally appears at the end of a document or book. This is distinct from a table of contents, a bibliography, or other supporting materials.

2. Begin with a completed text. If the text is not yet complete, you can still begin the process of building an index as long as the text has most of its final structure.

3. Review the entire text, marking key words and main ideas. In a word processing program that has indexing features, you may begin tagging them directly as you read (or even while you write if you’re keen). Otherwise, create sticky notes, index cards, or other markings on each page.

4. Assign headings to each key concept. Assigning good headings will make things easier for the reader to find, and will make the entire index self-consistent. While you should always check with the house style documentation with respect to creating an index, the following generalities are fairly standard:

5. Consider the likely reader and the purpose of the index.

6. Organize the main headings in alphabetical order. A word processor may be able to perform this step automatically.

7. Nest sub-headings under a main heading. Do not nest too many levels; stick to one or two. Nested headings collect related information under a main heading so that a reader can find it easily. Organize subheadings alphabetically beneath the heading.

8. List all the page numbers on which each subject appears.

9. Review the index for completeness and accuracy. If possible, have someone try out the index who is unfamiliar with the work.


Tips for writing an index:-

Refer to a completed index in another work as you begin.
Notice how the index goes together.
Consider hiring somebody to compile your index for you. Various freelancers and services will perform the work of indexing for a fee. If you do hire somebody, choose somebody with some understanding of the topic in question.
If you are writing for a particular publisher or publication, be sure to consult the relevant style guide. Some will have their own preferences as to formatting.
If you are using software to aid in the indexing process, use it for tagging key words and keeping track of pages. Using indexing software to generate the list of keywords or head words will at best give you a jumping-off point for further human review.
If you’re a copyeditor, you won’t usually get to read the index because it is usually created after you’ve participated the production process.
If you’re a proofreader, you will be expected to read the index very carefully and to check that its references are all accurate.



Be careful of missing significant topics when creating the index; go through the text and check against the index to ensure that all major topics and concepts have been covered.
Avoid indexing minor mentions. For example, if a famous person’s name has been mentioned in a quote but is not discussed anywhere else in the text, this person’s name is not index-worthy.
Think about the impression it would give the reader; be guided by the question: Would indexing it cause the reader to assume there is something substantial to read about the word or concept within the text?
Take care not to cross-reference in a circular manner. This will frustrate the reader because there will be no pointer added to let the reader know where to find the word or concept. For example: “Cycle. See Bicycle.” – “Bicycle. See Cycle.”
If using a word processor, double check that it hasn’t indexed an entire sentence from a section header that has no helpful referencing point. For example, a header might be called “Repairing bicycles isn’t easy” and the computer index might add the whole phrase. This doesn’t tell the reader anything helpful in terms of specificity of words or concept.

Sources:Wikpedia, Index (Publishing),
Suzanne Gilad, Copyediting and proofing for dummies, p. 205, (2007), ISBN 978-0-470-12171-9 
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