Regression discontinuity design (RD) has been widely used to produce reliable causal estimates. Researchers have validated the accuracy of RD design using within study comparisons (Cook, Shadish & Wong, 2008; Cook & Steiner, 2010; Shadish et al, 2011). Within study comparisons examines the validity of a quasi-experiment by comparing its…

Considering scoring validity as encompassing both reliable rating scale use and valid descriptor interpretation, this study reports on the validation of a CEFR-based scale that was co-constructed and used by novice raters. The research questions this paper wishes to answer are (a) whether it is possible to construct a CEFR-based rating scale with…

A research review supports the validity of the person-environment fit (PEF) model in vocational psychology; however, sampling inadequacies have influenced results. One PEF example, Holland's hexagonal model, is unsupported due to lack of commensurate measurement; most hexagonal congruence indices are invalid. (Contains 110 references.) (SK)

Includes "P-E [Person-Environment] Fit as Paradigm" (Dawis); "Pitfalls of Congruence Research" (Gati); "The Next Millennium of 'Fit' Research" (Hesketh); "Holland's Hexagon Is Alive and Well--Though Somewhat out of Shape" (Prediger); "Tinsley on Holland: A Misshapen Argument" (Rounds, McKenna,…

Content analysis of 364 articles in the Journal of Agricultural Education 1990-1999 indicated that a majority of studies did not mention nonresponse error as a threat to external validity, did not attempt to control for nonresponse error, or did not cite literature on handling it. Protocols to address nonresponse error were proposed. (Contains 24…

"How New York City's Charter Schools Affect Achievement" estimates the effects on student achievement of attending a New York City charter school rather than a traditional public school and investigates the characteristics of charter schools associated with the most positive effects on achievement. Because the report relies on an…

A new report published by the Buckeye Institute for Public Policy Solutions is a minor variant on six similar reports published by the Friedman Foundation over the past three years. The new report repeats some of the errors in the previous reports, and it follows a parallel structure, arguing that the costs of dropping out are dramatic for the…

The use of stepwise regression has been criticized for both interpretive misunderstandings and statistical aberrations. A major statistical problem with stepwise regression and other procedures that involve multiple significance tests is the inflation of the Type I error rate. General approaches to control the family-wise error rate such as the…

Abuses and misuses of statistics are frequent. This digest attempts to warn against these in three broad classes of pitfalls: sources of bias, errors of methodology, and misinterpretation of results. Sources of bias are conditions or circumstances that affect the external validity of statistical results. In order for a researcher to make…

The sampling of teachers for nationwide surveys offers a challenging endeavor in obtaining a representative and adequate sample to truly represent opinions of the teachers. Ten national surveys of public school teachers conducted between 1980 and 1985 are presented with respect to their sampling design and procedures. Concepts and theoretical…