Web Analytics: Sessionisation Methods Part 4 (Session IDs)
Non-cookie Sessionisation Methods
2. Session Parameter/ID - Another non-cookie based sessionisation method is the use of session parameters/ID’s. Compared to using IP-based methods (both IP only and IP plus agent) the use of session IDs actually result in more accurate visit-related metrics. The reason for this is that while IP-based methods gather data by looking at the assigned IP of the machine with this other method session IDs, which are simply random numbers and letters, are assigned to each visitor and sent back and forth allowing the visited site to gather data for each step taken by the visitor. Note that session IDs are erased at the end of each visit so that just like IP-based methods this does not allow for the gathering certain data that can be used to compare repeat visitors and first-time visitors.
Session IDs is non-cookie based sessionisation method but you should remember that session IDs are also often used for cookie-based methods. In cookie-bases sessionisation methods the session IDs are simply stored in cookies. In this case you get even more accurate visit-related metrics. But then again don’t forget that cookies are not allowed for US government sites.