An important issue in educational and employment settings is the degree to which evidence of validity obtained in one situation can be generalized to another situation without further study of validity in the new situation. Theory, procedures, and applications concerning validity generalization are addressed. Meta-analytic techniques make possible…

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…

Too few researchers understand what statistical significance testing does and does not do, and consequently their results are misinterpreted. This Digest explains the concept of statistical significance testing and discusses the meaning of probabilities, the concept of statistical significance, arguments against significance testing,…