The impact of misspecifying covariance matrices at the second and third levels of the three-level model is evaluated. Results indicate that ignoring existing covariance has no effect on the treatment effect estimate. In addition, the between-case variance estimates are unbiased when covariance is either modeled or ignored. If the research interest…

A valuable extension of the single-rating regression discontinuity design (RDD) is a multiple-rating RDD (MRRDD). To date, four main methods have been used to estimate average treatment effects at the multiple treatment frontiers of an MRRDD: the "surface" method, the "frontier" method, the "binding-score" method, and…

It is a widely held belief that anchor tests should be miniature versions (i.e., minitests), with respect to content and statistical characteristics of the tests being equated. This paper examines the foundations for this belief. It examines the requirement of statistical representativeness of anchor tests that are content representative. The…

The purpose of this simulation was to assess the improvements in estimates of standard errors that could be expected if students participating in NAEP were pre-assigned to test booklets that were adapted to their level of performance based on their state assessment scores. Students in extreme quartiles would receive one regular NAEP block and…