An aggregation strategy is proposed to potentially address practical limitation related to computing resources for two-level multidimensional item response theory (MIRT) models with large data sets. The aggregate model is derived by integration of the normal ogive model, and an adaptation of the stochastic approximation expectation maximization…

Theoretical analysis of whole number-based calculation strategies and digit-based algorithms for multi-digit multiplication and division reveals that strategy use includes two kinds of reasoning: reasoning about the relations between numbers and reasoning about the relations between operations. In contrast, algorithms aim to reduce the necessary…

The purpose of this study was to determine whether patterns of strategy use in second, third and fourth grade children's arithmetic supported Steffe's model of numerical development. In addition to student-generated strategies, we looked at commonly taught algorithms not considered in Steffe's model to determine whether these algorithms reflected…

In the IEA PIRLS International Report, a number of indices of reading-related constructs were introduced for the purpose of explaining the variation in reading achievement. These indices, however, raise issues of reliability and validity, due to the way in which they are derived and due to the quality of the data. Targeting these issues, the…