Very little is known about the quality of the learning experiences provided for pupils. This book contains the results of a major research project, conducted in a sample of English primary schools, in which particular attention was paid to the tasks children were assigned, to the degree of match between assigned tasks and pupil attainment, to the detailed observation of children at work. The teacher's problems in assigning work appropriate to children's attainments and the special problem of matching posed by the transfer of children from one class to another were also subjected to analysis. Lessons learned from the project were used as a basis for the design of an in-service course for teachers. The course, which was aimed at improving teachers' matching skills was closely evaluated. The report contains data and analysis pertinent to each of the above issues. The findings reveal that despite the conscientious efforts of able teachers a number of serious issues are apparent -- particularly in areas such as classroom organization and teacher diagnosis of children's work.