Preferably, the same indexing technique is used for both the first and second level of indexing.

The indexing technique can be effective even in the presence of variables which are not highly correlated.

All data are sorted by an indexing technique created specifically for the occasion.

A cipher system (10) uses an indexing technique in a dual system cipher in dual pairing vector spaces.

A word indexing technique for crossing page boundaries within a document is also disclosed, as well as a technique for enumerating and displaying virtual folders and their contents.