An information retrieval system allows a user to navigate through a plurality
of informational items for a desired informational item, and upon selection of
an informational item, presents other informational items related to the selected
informational item. The information retrieval system in accordance with the principles
of the present invention maintains a database that defines a relational association
between a plurality of informational items in the system. The relational association
is based on historical navigational behavior of users of the information retrieval
system, and includes a relationship type, which is based on the characteristic
similarities between the informational items, and relationship strength, which
is based on the historical frequency of any related informational items being selected
by a user within the same information retrieval session. When a navigation from
one informational item to another informational item is detected, the relationship
type and the relationship strength of the two informational items are determined
and stored in the database. During a subsequent selection of an informational item,
any related informational items related to the selected informational item are
sorted based on the respective relationship types and relationship strengths, and
are provided in a sorted list from which the user can select.