This paper described a new approach to user modeling in adaptive e-learning systems, taking into account contextual aspects to improve personalization capabilities. The main features of our approach are explained and illustrated and we detail each contextual dimension such as personal, educational, technological and specially cultural context. We present some examples from AdaptWeb® and show how context and culture could be modeled for personalization, making use of a set of ontologies for representing explicitly this rich context as an extension of traditional student modeling