This study involved 179 9-year-olds and 352 13-year-olds in New Zealand. Four addition and four subtraction tasks were set to ascertain students' ability to use the number line. Comparison of these data with results from the national assessment in the United States are given. (MNS)

False positive and false negative error rates were studied for competency testing when failing examinees are permitted to retake the test. Formulas are provided for the beta-binomial and Rasch models. Estimates based on these models are compared for six data sets from the South Carolina Basic Skills Assessment Program. (SLD)

How computers have affected diagnosis in mathematics is discussed. A distinction is made between errors and mistakes, followed by consideration of computers as a diagnostic tool. The development of algorithms to diagnose errors and of models of student performance is described. (MNS)

This study introduced a probabilistic model utilizing item response theory (IRT) for dealing with a variety of misconceptions. The model can be used for evaluating the transition behavior of error types, advancement of learning stages, or the stability and persistence of particular misconceptions. Moreover, it apparently can be used for relating…

Research was conducted investigating properties of skill in learning, in the domain of elementary algebra. Thinking-aloud protocols indicate that early knowledge of the subjects studied was fragmentary, rather than involving systematically flawed procedures. Computational models, developed to simulate observed errors, focused on the role of…