The NATO workshop ''Knowledge acquisition in the domain of physics and intelligent learning environments" was held in Lyon, France, July 8-12, 1990. A total of 31 researchers from Europe (France, Germany, Greece, Italy, Portugal, and the U. K. ), the U. S. A. , and Japan worked together. This proceedings volume contains most of the contributions to the workshop. The papers show clearly the main directions of research in intelligent learning environments. They display a variety of points of view depending on the researcher's own background even when a single domain of teaching, namely physics, is considered. We acknowledge the assistance of Michael Baker, who was responsible for reviewing the English of the contributions. February 1992 Andree TIberghien Heinz Mandl Table of Contents Introduction 1 1. Teaching Situations and Physics Knowledge Introductory University Courses and Open Environment Approaches: The Computer as a Multi-role Mediator in Teaching/Learning Physics 5 E. Balzano, P. Guidoni, M. Moretti, E. Sassi, G. Sgueglia Practical Work Aid: Knowledge Representation in a Model Based AI System 21 J. Courtois Simultaneous Processing of Different Problem Aspects in Expert Problem Solving: An Analysis in the Domain of Physics on the Basis of Formal Theories of Commonsense Knowledge 35 A. Hron Modelis: An Artificial Intelligence System Which Models Thermodynamics Textbook Problems 47 G. Tisseau 2. Different Approaches to Student Modelling Steps Towards the Formalisation of a Psycho-logic of Motion 65 J. Bliss, J.