Association for the Advancement of Computing in Education ( AACE ) . Distributed via the Web by permission of AACE . Shared User Behavior on the World Wide Web

Studying accesses to Web servers from different user communities helps identify similarities and differences in user access patterns. In this paper we identify invariants that hold across a collection of ten traces representing traffic seen by proxy servers. The traces were collected from university, high school, governmental, industry, and online service provider environments, with request rates that range from a few accesses to thousands of accesses per hour. In most of the workloads a small portion of the clients are responsible for most of the accesses. In addition most of the accesses go to a small set of servers. By doing a longitudinal study on the collected data we noticed that the identified invariants do not change over a year period. However, the percentage of script generated documents, is increasing.