Describes hypothesis validity as extent to which research results reflect theoretically derived predictions about relations between or among constructs. Discusses role of hypotheses in theory testing. Presents four threats to hypothesis validity: (1) inconsequential research hypotheses; (2) ambiguous research hypotheses; (3) noncongruence of…

Responds to Gordon's critique (in this issue) of Bohannon and Stanowicz (1988) by pointing out relevant and irrelevant aspects of discussions of learnability. Rates of feedback found in Bohannon and Stanowicz are shown to be sufficient to spur learning in many species. Evidence against the universality of negative evidence is discounted. (RH)

Notes that, when planning research, obvious strategy is to assess likely flaws and develop approaches to overcome them. Introduces set of concepts that researchers can use to evaluate quality of their designs. Presents 32 threats to validity organized according to 4 types of validity (internal, external, statistical conclusion, and construct…

Notes that studies in psychology often have low power because of inadequate sample size and that prevalent psychometric distributions are sometimes radically nonnormal. Demonstrates robustness of independent samples t-test with respect to Type I error. Shows that researchers may use power tables based on population normality without modification…

Comments on Robinson and Gross's article on perceptions of ethics among mental health counselors. Argues researcher needs to discuss findings, regardless of what path it may lead down. Three explanations are given as possible reasons for their findings, two avoiding gender stereotypes in whole or in part. (Author/ABL)

Reviews misuse of statistical tests in psychotherapy research studies published in "Journal of Consulting and Clinical Psychology" in 1967-68, 1977-78, and 1987-88. Focuses on inappropriate uses of null hypotheses tests and p values, neglect of effect size, and inflation of Type I error rate. Concludes with practical suggestions for rational…

This study examined whether having a Teach For America (TFA) teacher instead of a non-TFA teacher affects the academic performance of high school students. The research described in this report is consistent with What Works Clearinghouse (WWC) evidence standards with reservations. The following strengths were identified. The estimated effects rely…

"The Negative Impacts of Starting Middle School in Sixth Grade" examined whether placing sixth graders in middle schools rather than elementary schools affects their behavior and academic performance. The What Works Clearinghouse (WWC) has reservations about the results because they may be affected by differences between the research…

This article presents the author's address at the 2007 "Journal of Applied Quantitative Methods" ("JAQM") prize awarding festivity. The festivity was included in the opening of the 4th International Conference on Applied Statistics, November 22, 2008, Bucharest, Romania. In the address, the author reflects on three theses that…

Studies of group differences in intelligence often invite conclusions about groups in general from studies of group differences in selected populations. The same design is used in the study of group differences in other traits as well. Investigators observe samples from two groups (e.g. men and women) in some accessible population, but seek to…

This article describes the methodology and observational data from a project that sought to, first, investigate the prevalence of alcohol related harm and alcohol misuse in Cardiff's night-time economy and, second, deliver a targeted server training intervention to premises identified as at risk of misselling alcohol. The bulk of the work is…

The professional development school (PDS) is a model of choice for many teacher preparation programs. This approach integrates the functions of teacher preparation, professional development, inquiry and research, and student achievement to bring about whole-school improvement and the simultaneous renewal of the teaching profession. Ideally,…

Chemists have used computational science methodologies for a number of decades and their utility continues to be unabated. For this reason we developed an advanced lab in computational chemistry in which students gain understanding of general strengths and weaknesses of computation-based chemistry by working through a specific research problem.…

Despite having drawn from empirical evidence and cumulative prior expertise in the formulation of research questions as well as study design, each study is treated as a stand-alone product rather than positioned within a sequence of cumulative evidence. While results of prior studies are typically cited within the body of prior literature review,…

The Education Trust research report "Stuck Schools" suggests a framework for identifying chronically low-performing schools in need of turnaround. The study uses Maryland and Indiana to show that some low-performing schools make progress while others remain stagnant. The report has four serious problems of reliability and validity,…