This volume in the NATO Advanced Educational Technologyprogram gives a comprehensive overview of the field ofstudent modelling. Student modelling,a special case of usermodelling, gives an intelligent tutoring system thecapability to individualize its interactions with a student. The book collects together contributions from many of theworld's leading authorities on student modelling. Theyinclude formalists, knowledge engineers, and cognitivescientists, to give the book an interdisciplinary flavourthat enriches the treatment. The editors have written anoverallintroduction that helps to integrate the many ideasin the book. This is a unique, comprehensive, and up-to-datetreatment of the field.