The use of techniques from the field of autonomous agents provides a new complementary style of human-computer interaction, where the computer becomes an intelligent, active and personalized collaborator. Interface agents are computer programs that employ Artificial Intelligence methods to provide active assistance to a user of a particular computer application. The metaphor used is that of a personal assistant who is collaborating with the user in the same work environment. The assistant becomes gradually more effective as it learns the user's interests, habits and preferences