8. Indexing

Editing an Index

While creating the first draft of your index, you probably concentrated mostly on the individual entries and their secondary entries. While editing the index, you are concerned with the index as a whole.

Editing an index may require that you create or delete entries, combine or split up entries, and regroup or reword entries. In a sense, editing an index is not very different from editing the document. Namely, you verify that all necessary material is included, that it is in the intended order, and that it is error-free.

Remember that you are reading an index in an abnormal way; that is, you are reading it from start to finish. Normally, your readers go directly to the word or phrase they hope to find. Because you are reading an index this way, you may think that many entries are not necessary or are redundant. For some entries, this may be true, but to delete many entries on that basis alone is risky. Unless your analysis of the topic was wrong when you created the entry, you probably had a specific reason for making the entry.

Check the Spelling

Many publishing systems don't check the spelling in the embedded index entries when the spelling checker is run on the body of the document. For this reason, you should always carefully proofread and run the spelling checker on index entries to catch spelling and typographical errors.

Check the Levels of Secondary Entries

Check the levels of secondary entries so that proper indentation shows the relationship of one entry to the preceding one. See "Nested Entries."

Check for Differences in Wording

Check the subjects to determine whether slight variations of wording are intentional or whether you should use only one wording. If there are valid subjects that differ only slightly in wording, examine them to be sure that your readers are able to recognize the differences; you may have to reword the subjects to make the differences apparent.

Many times you will discover after creating the index that you have used inconsistent terminology in the document. This is a good time to check for consistency and make any necessary corrections, even though it means taking a little more time.

Check for Misused Singular and Plural Forms

Check the entries for the misuse of singular and plural forms. Usually, only one form of a subject is justified; therefore, you should combine secondary entries under one subject. Using both forms of a subject (such as "data set" and "data sets") usually causes errors. Several other entries and their subsequent secondary entries may intervene between the singular and plural forms of a subject. A reader should not have to check the index for both forms.

Wrong              Right
data set           data sets
   input              address
   output             area
data set address      format of
data set area         input
data sets             output        
   format of          table of             
   table of                      

Check for Redundant Secondary Entries

Check main entries that are followed by secondary entries having the same page reference.

In many cases, you can eliminate the secondary entries because a reader will find all the information on one page. Redundant secondary entries often occur when indexing items in a table. See "Don't Over-Index."

Wrong              Right
data sets          data sets, 2-7
   format of, 2-7                   
   table of, 2-7                    

Check for Effective Double-Posting

Check that all meaningful variations of a subject's wording appear in an index. See "Group Entries."

Check Secondary Entries for Possible Primary Entries

Check each secondary entry to see if it should also appear as a primary entry. If it should, verify that it exists as such or create the primary entry and insert it in the proper place.

Check for Possible Rearrangement of Secondary Entries

Check if secondary entries should be rearranged to stress a certain point. In this example, all three secondary entries should probably be in the same form. The form depends on what you want to stress.

Wrong                       Right
window system               window system
   colors, changing, 8-11      colors, changing, 8-11
   icon, moving, 4-22          icon, moving, 4-22
   saving properties, 8-15     properties, saving, 8-15

Check for Appropriately Combined Secondary Entries

Review an index to make sure that you have combined relevant entries.

Wrong                                    Right
DeskSet                                  DeskSet
   selection protocol, 2-4                  atoms, 4-8
DeskSet atoms, 4-8                          drag and drop
DeskSet Drag and Drop atoms, 4-4               atoms, 4-4
DeskSet drag and drop handshaking, 4-2         handshaking, 4-2
deskset integration, 1-2                    integration, 1-1, 1-2
   why do it, 1-2                           selection protocol, 2-4       

Check for Secondary Entries Under More Than One Subject

Check for secondary entries that should be arranged under one subject rather than appearing under several. Such division of secondary entries is usually the result of misused "See also" references.

Wrong                           Right
find function                   find function
   See also search function        dialog box, 8-9
   examples, 8-22                  examples, 8-22
   use of, 8-15                    and replace function, 8-21
   variables, 8-18                 use of, 8-15
.                                  variables, 8-18
.                               .
.                               . 
search function                 .
   dialog box, 8-9              search function, See find function
   and replace function, 8-21                                        

Check for Secondary Entries When Using a Combined Term Separately

Check for and move a secondary entry if you included the combined term as a separate entry.

In the next example, the entries starting with "database" under the "classing engine" main entry belong under the "classing engine database" main entry.

Wrong                              Right
classing engine                    classing engine
   adding a new file type, 6-6        adding a new file type, 6-6
   attributes, 6-4                    attributes, 6-4
   database, accessing, 6-7           interactive modification, 6-5
   database, converting, 6-8          mapping function, 6-3
   database, reading, 6-8          classing engine database
   interactive modification, 6-5      accessing, 6-7
   mapping function, 6-3              converting, 6-8
classing engine database              location of, 6-7
   location of, 6-7                   network, 6-9
   network, 6-9                    reading, 6-8

Check the Number of Page References for Entries

Depending upon the complexity of your material, each index entry should have no more than two to four page references. If an entry has more than two to four page references, see if you can create secondary and tertiary entries to reduce the number of page references.

Wrong                           Right
block diagram, 21, 28, 33, 37   block diagram
                                   attribute generator, 33
                                   frame buffer, 37
                                   front-end processor, 28
                                   SBus adapter, 21

Check the Proper Topic Cross-References

Check that the page references for each occurrence of a topic are the same and that they appear in each place. In the example, a reader looking up "operator messages" would not be aware of all the other places where information exists. Create secondary entries under "operator messages" and give your readers the same information they would have found had they looked up "messages."

Wrong                          Right
messages                       messages
   from operator, 2-34            from operator, 2-34
   to operator, 2-15, 3-7         to operator, 2-15, 3-7
   to programmer, 5-12            to programmer, 5-12
   .                              .
   .                              .
   .                              .
operator messages, 2-34, 3-7   operator messages, 2-34, 3-7
	.                         from operator, 2-34
	.                         to operator, 2-15, 3-7
	.                         to programmer, 5-12

Check the Secondary Entries Under Various Forms of One Topic

Check that the number of secondary entries under various forms of the same topic are all the same. In the example, "attention key" should appear after the "terminal, communications" entry so that readers are aware of the information regardless of how they look it up.

Wrong                        Right
communications terminal      communications terminal
   attention key, 4-16          attention key, 4-16
   polling character, 4-11      polling character, 4-11
   READY indicator, 4-10        READY indicator, 4-10
   .                            .
   .                            .
   .                            .
terminal, communications     terminal, communications
   polling character, 4-11      attention key, 4-16
   READY indicator, 4-10        polling character, 4-11
                                READY indicator, 4-10

Check the "See" and "See Also" References

Check that each "See" reference refers to an entry with secondary entries. Read "Creating "See" and "See Also" References."

Check the Size of the Index

After you have edited the index, compare the size of the index with the size of the document. Although the index size is not an indication of its quality, an index that is too small for the size of the document should make you suspicious; it might indicate serious omissions.

A minimum length for an index should be one page of index entries for every 20 pages of text, or about one index entry for every 100 words of text. This would be considered a "5 percent" index. For dense technical material; however, this guideline is too low. A dense technical manual should have one page of index entries for every 10 pages of text, which would be considered a "10 percent" index.

If you check the length of your index by page count (rather than by word count), do not count text pages that contain any of the following if they occupy more than about two-thirds of a page:

If the index falls below the guidelines, check that all topics in the document are entered in the index.

Correct Bad Page and Column Breaks

One form of bad page break results when a primary entry with multiple secondary entries (or even tertiary entries) breaks in the middle at the foot of the last column on a right page. The first column on the following page begins with an indented (secondary or tertiary) entry. Bad page breaks cause problems for a reader, who must look back to the previous page to find the primary entry.

Correct bad page breaks by repeating the primary entry above the carried-over secondary entry followed by the word continued in italics and surrounded by parentheses. Don't repeat the page numbers, if included, from the previous primary or secondary entry. In the example, the primary entry "menus" includes a page range, but the page range is not repeated on the next page.

    menus, 3 - 22              menus (continued)
       general navigation, 3      Graphics, 16
       Edit, 8                    Special, 20
       File, 10                   Table, 21
       Format, 12                 View, 22

In the rare case where this type of bad break occurs on a secondary entry with multiple tertiary entries, repeat the primary entry at the top of the column. Then, repeat the secondary entry, indented, followed by the word "continued." Do not include the word "continued" after the primary entry.

    graphical user interface       graphical user interface
       menus                          menus (continued)
       general navigation, 3             Graphics, 16
          Edit, 8                        Special, 20
          File, 10                       Table, 21
          Format, 12                     View, 22

A single primary entry at the beginning of an alphabetic section should not stand at the bottom of a column. Force the alphabetic character to the top of the next column, carrying the single primary entry along with it.

Likewise, don't leave a single line at the end of an alphabetic section at the top of a column. Force a column break one or two lines before the widowed line.