A guide for professional counselors and counseling researchers for calculating and interpreting Percent Improvement as an indicator of clinical significance is provided. Strategies for reporting findings are described and illustrated. Guidelines for contextualizing discussions of clinical significance within the boundaries of psychometric evidence…

Use of "special" orthonormal mean contrasts and mean contrast variances can help educational researchers interpret a wide variety of repeated measures data. Most statistical packages allow educational researchers to test for differences across repeated measures using both the univariate mixed model F test and a multivariate test.…

The high incidence of reported posttraumatic stress disorder (PTSD) among Vietnam veterans has prompted researchers to search for reliable assessment and treatment procedures for this disorder. Although some encouraging preliminary data on the use of the Minnesota Multiphasic Personality Inventory (MMPI) have been obtained, it is uncertain if this…

This paper evaluates the logic underlying various criticisms of statistical significance testing and makes specific recommendations for scientific and editorial practice that might better increase the knowledge base. Reliance on the traditional hypothesis testing model has led to a major bias against nonsignificant results and to misinterpretation…