This tab displays, in tree form, a list of the words that occur in all uncategorized e-mails.
The index tree consists of folder icons, each labeled with a word, with the number of occurrences (number of e-mails it occurs in) in square brackets. These words can be called head words.
Each head word folder expands to a list of the words that co-occur with the head word. Each co-occurring word is followed by square brackets containing two numbers: the number of e-mails this word occurs in, and a ratio. This ratio is the rate of occurrence with this head word divided by rate of occurrence in whole corpus. For example:

This part of the index tree includes the following information:
magazines occurs in seven uncategorized e-mails
articles occurs in three of those seven e-mails, which is 4.4 times as often as it occurs in the entire corpus of uncategorized e-mails.
Of the three e-mails containing magazines and articles, two also contain newsstand. This is 13.7 times as often as newsstand occurs in the entire corpus.
This indicates that the words articles and newsstand are highly likely to occur together, which means e-mails that contain both words are good candidates for grouping together in a category.
At the bottom of the tab are the following boxes and buttons:
Find Words
Min. Texts
with words
Rebuild
Index Tree
Select Texts
For more details on the Indexing tab, see the "Indexing Tab" section in the "Genesys Knowledge Management: Content Analyzer" chapter of the Multimedia 7.6 User's Guide.