A user is defined as a single
individual that accesses files from web servers through a
browser. A web log sequentially records users’ activities
according to the time each occurred. In order to study the
actual user behavior, users in the log must be distinguished.
Figure 1 is a sample Web site where nodes are pages, edges
are hyperlinks, and node “/index.php” is the entry page of this
site. The edges are bi-directional because users can easily use
the back button on the browser to return to the previous page.