Estimation problems associated with the correlated-trait correlated-method (CTCM) parameterization of a multitrait-multimethod (MTMM) matrix are widely documented: the model often fails to converge; even when convergence is achieved, one or more of the parameter estimates are outside the admissible parameter space. In this study, the authors…

Sampling tasks and sampling distributions provide a fertile realm for investigating students' conceptions of variability. A project-designed teaching episode on samples and sampling distributions was team-taught in 6 research classrooms (2 middle school and 4 high school) by the investigators and regular classroom mathematics teachers. Data…

Survey research has played a major role in American social science. An outgrowth of efforts by the United States Department of Agriculture in the 1930s, the Division of Program Surveys (DPS) played an important role in the development of survey methodology. The DPS was headed by the ambitious and entrepreneurial Rensis Likert, populated by young…