Machine learning for user modeling

At first blush, user modeling appears to be a prime candidate for straightf orward application of standard machine learning techniques. Observations of the user's behavior can provide training examples that a machine learning system can use to form a model designed to predict future actions. However, user modeling poses a number of challenges for machine learning that have hindered its application in user modeling, including: the need for large da ta sets; the need for labeled data; concept drift; and computational comple xity. This paper examines each of these issues and reviews approaches to re solving them.