Abstract: In this paper, using the information obtained from the daily working of a Web directory, we attempt to expand the knowledge about the behaviour of the users in order to improve and adapt the Internet search engines to their users. We have analysed more than 320,000 requests of the transaction log of a Spanish Web directory, focusing our attention, firstly, in the searches in order to confirm the main differences between Internet and traditional Information Retrieval systems. Furthermore, we have developed an exhaustive statistical analysis of searches, categories visited and documents viewed to achieve a mathematical pattern of behaviour for each one, and what it is more important, to establish a relationship between the variations in the behaviour of each one.