9255272 Wilson This proposal from Mark Wilson and Raymond Adams is intended to develop a new testing technology that focuses on student constructed understandings of mathematics. It is a psychometric study to develop multidimensional models of sufficient flexibility to examine test issues of reliability, validity, and equity. The investigators use a methodological approach within Item Response Theory using recent performance tests carried out in California and Melbourne Australia. The project would extend measurement models to incorporate multidimensionality, develop computer programs to calibrate items and raters, re-analyze performance assessments in mathematics to study validity of each mode of assessment, and collect performance assessment data to study longitudinal aspects of student measures.