In this paper, we describe a Web-based system that defines training needs for object-oriented developers by identifying the strong and the weak areas of their knowledge and skills. The system is based on the use of two tools, GAA [8] and UKAT [3], developed at the Computer Research Institute of Montreal (CRIM). UKAT (User Knowledge Assessment Tool) uses a state-of-the-art knowledge assessment method to create a user profile of the proficiency in a subject domain. GAA (Intelligent Guide) is a Web-based training system that uses the UKAT to personalize a training course and facilitate self-learning. Keywords Internet-based training, object-oriented technology, knowledge and skills assessment, self-learning resources.