(Originally published in The Technical Editor, March 1999, Institute of Technical Editors. Updated June, 2007.)
Like any well-written document, an index needs to be edited. Editing ensures consistency, clarity, completeness and accuracy. And an effective index contributes substantially to the usability of a document.
Indexes assist users to find specific information within a document, in print or online. As such, index headings refer to concepts, tasks or objects—not simply to individual words in the text.
Three types of relationships serve to link index headings together:
Editing an index can take almost as much time as writing the first draft—and possibly longer if the index markers embedded in the main document are difficult to access. Editing requires close attention to both detail and the overall structure of the index.
Although time consuming, be sure to correct the index markers in the main document rather than editing the text of a generated index directly. Otherwise, when you regenerate the index, all your editing will disappear. Professional indexers often use specialized stand-a-lone indexing software to help them write and edit an index quickly; once complete, the index headings can be sorted by page number and the index markers entered into the main document.
This article provides a checklist of items to assist you:
Main HeadingsEvaluate main headings individually bearing in mind that they form the primary access points to the index. Does the heading reflect the material in the main document? Is the heading clear and concise? Does the wording reflect what the user would look up?
Index headings should reflect a consistent level of depth across the document.
Archaeology, 128–145In the above example, the heading for "Archaeology" needs to be expanded to match the level of depth in the "Architecture" heading. Subheadings will enable users to quickly find specific information about archaeology.
SynonymsSynonyms allow users to use their own words when searching for information. You might ask your client to review the main headings in the index and suggest any synonyms. Look at competitors’ manuals for their terminology, especially if you seek to attract customers from other camps. Consider terms used in other environments, e.g., Mac, PC or Unix. User analysis, such as contextual inquiry, may reveal user terminology as well.
You may enter a synonym
Great War 1914–18. See First World War
Number of Undifferentiated Page ReferencesIn a technical publication, there should ideally be only one or two page references in a main heading or subheading. Undifferentiated page references simply cause additional work for users, who may already feel frustrated. More than three or four undifferentiated page references usually indicates a problem.
If a main heading has too many undifferentiated page references, simply create a number of subheadings.
Platemaking, 78, 79–80, 84, 86, 90 See also Process camerato
Platemaking, See also Process cameraIn a two level index, if there are too many undifferentiated page references in a subheading, you cannot simply divide the subheading into sub-subheadings. One solution is to raise the subheading to a main heading with its own subheadings and make a "See also" cross-reference from the original main heading.
media elements 340–345
Number of Subheadings Following a Main HeadingAs a rule of thumb, more than 15 or so subheadings following a main heading may indicate a structural problem. The following example comes from a manual about using fax software on a PC.
faxIn this example, the main heading is too broad, given that the manual is about faxing. To fix the problem, simply eliminate the main heading and raise the subheadings to main headings.
Parallel Structure in SubheadingsTo the extent possible, try to follow a consistent grammatical structure in subheadings.
Double-Posted HeadingsVerify that the subheadings and page references match in any double-posted headings. In the following example, the main headings are synonyms; so the subheadings and page references must be exactly the same in both the headings.
directories 21–25In this next example, "saffron" appears as a subheading under "Rice," and "rice" appears as a subheading under "Saffron."
RiceIf subheadings are missing from an heading, a user may look at the heading and conclude that a topic is not covered in the document, when in fact it is.
Subheadings that users may wish to look up directly should also be posted as main headings. In the following example, "balusters" is listed as a subheading under "porches" and is also posted as a main heading.
Cross-referencesCheck that each cross-reference ("See" and "See also") refers to an heading and that they match exactly. Also check for circular cross-references. In the example below, the "See also" reference under "annotations" is circular and should be removed.
annotations 203Also ensure that cross-references go directly to an heading, not to another cross-reference. In the example below, the "See also" reference under "weight control" should be changed to go directly to "fitness."
Alphabetization of SubheadingsLeading articles and prepositions in subheadings should not be alphabetized. In FrameMaker you can define how to alphabetize a specific subheading; however, in Microsoft Word you will need to fix the index manually after it’s generated. In the following example, "into or out of an" in "into or out of an eddy" and "on" in "on University River" are ignored when alphabetizing the list of subheadings.
Back ferry (setting)In general, only use articles or prepositions when necessary to clarify meaning.
Capitalization, Pluralization and SpellingEstablish a style for capitalization. Older style indexes often capitalize the first letter of each main heading. In technical documentation, it’s wise to follow the capitalization used in the text because capitalization can affect the meaning of specific terms or may be incorrect if changed.
OPEN LOOKGenerally, nouns where we can ask "how many?" are expressed in the plural form.
animalsNouns where we can ask "how much?" are usually expressed in the singular form.
energyDecide on how you will handle pluralization and be consistent throughout the index.
Be careful about American, Canadian and British spellings. Employ the spelling used in the main document.
Personal and Geographic NamesMany rules apply to personal names. Generally, you enter the surname followed by forename or initials.
Freud, SigmundSpecial rules apply to handling prefixes in French, German and other European names. Different rules may apply to names of Asian origin as well.
Am Thym, AugustNames of geographic features that begin with the type of feature, such as Mt. or Lake, are inverted when entered in the index.
Ontario, LakeOn the other hand, you do not invert proper place names that begin with a type of feature.
Cape Scott Provincial ParkFor specific guidance on handling personal and geographic names, see Mulvany pages 152–182 or The Chicago Manual of Style (14th edition) pages 731–737. For the correct spelling or form of a personal name, you may wish to check a standard reference source such as Merriam-Webster’s Biographical Dictionary or the Encyclopedia Britannica.
Page References are AccurateCheck a small number of page references (e.g., 5%) to ensure that nothing has gone wrong. When an index is embedded in a document, sometimes one can forget to regenerate the index after making final changes to the text.
Mechanics for an Online IndexIn online indexes, check that hypertext links and any automated search capabilities work properly.