ABSTRACT
This chapter details a report of an investigation for the field of Special Education into the effects of class heterogeneity on teacher behavior, pupil behavior and pupil achievement. The aim of the study is to find those teacher behaviors that are positively related to high achievement-gain-scores and to answer the question if those behaviors are influenced by class composition. The investigation has been carried out in 20 classes of schools for Special Education for primary learning disabled children in the Netherlands. According to Thompson teacher behavior was divided into three main categories: academic behavior, immediately directed to the task; procedural behavior, task preparation behavior; management behavior, directed to managing pupil distractions, pupil off-task behavior and so on. Pupil behavior was also divided into three main categories: on-task, procedural and off-task behavior. According to Van der Leij the intensity level of teacher behavior from the point of view of the pupil is an important aspect, especially in Special Education.
