Background: Large-scale cross-national studies designed to measure student achievement use different social, cultural, economic and other background variables to explain observed differences in that achievement. Prior to their inclusion into a prediction model, these variables are commonly scaled into latent background indices. To allow…

Describes the development of the performance assessment tasks of the Third International Mathematics and Science Study. The challenge was to produce tasks that would measure the achievement of curricular objectives while being sufficiently reliable to allow comparisons between countries and of groups within countries. (SLD)