Add to ORKGLately, many approaches have been developed to discover computer abuse. Some of them use data mining techniques to discover anomalous behavior in audit trail, considering this behavior as an intrusive one. This paper discusses a temporal knowledge representation of users' behavior that is used by data mining tools to construct behavior patterns. These are used to decide whether current behavior follows a certain normal pattern or differs from all known users' behavior patterns. The representation uses Allen's temporal interval algebra to describe the temporal relations between events caused by the user. Also we discuss how our representation is used to help in the concept drift when the set of training samples is reduced by r...