The present study aimed at clarifying the various shortcomings of the Cohen's criteria for the interpretation of the values of the practical significance indicators. The hypothetical data were used for two experimental and control groups and calculating the paired-samples t-test. To clarify the inadequacy of Cohen's criteria in interpreting…

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…

Recent research has proposed a criterion to evaluate the reportability of subscores. This criterion is a value-added ratio ("VAR"), where values greater than 1 suggest that the true subscore is better approximated by the observed subscore than by the total score. This research extends the existing literature by quantifying statistical…

Null hypothesis significance testing (NHST) has been the subject of debate for decades and alternative approaches to data analysis have been proposed. This article addresses this debate from the perspective of scientific inquiry and inference. Inference is an inverse problem and application of statistical methods cannot reveal whether effects…

The subject of the research is focused on questioning teachers' attitudes in reference to using ICT competencies in the classroom, considering the gender, years of service and education, while the problem of the research concerns the question: What are the teachers' attitudes in reference to using ICT competencies in the classroom? Regarding to…

In this paper, we report a case study that illustrates the importance in interpreting the results from statistical tests, and shows the difference between practical importance and statistical significance. This case study presents three sets of data concerning the performance of two brands of batteries. The data are easy to describe and…

Correlated predictors in regression models are a fact of life in applied social science research. The extent to which they are correlated will influence the estimates and statistics associated with the other variables they are modeled along with. These effects, for example, may include enhanced regression coefficients for the other variables--a…

The authors of the study "The Long-Term Impact of Teachers" claim that their study shows that increases in teacher value-added lead to significant and lasting increases in test scores and significant increases in income that will last throughout adulthood. Instead, I show that these claims are false because they are contradicted by the…

The use of confidence intervals (CIs) as an addition or as an alternative to null hypothesis significance testing (NHST) has been promoted as a means to make researchers more aware of the uncertainty that is inherent in statistical inference. Little is known, however, about whether presenting results via CIs affects how readers judge the…

The Journal of Agricultural Education (JAE) requires authors to follow the guidelines stated in the Publication Manual of the American Psychological Association [APA] (2009) in preparing research manuscripts, and to utilize accepted research and statistical methods in conducting quantitative research studies. The APA recommends the reporting of…

Null hypothesis significance testing has dominated quantitative research in education and psychology. However, the statistical significance of a test as indicated by a p-value does not speak to the practical significance of the study. Thus, reporting effect size to supplement p-value is highly recommended by scholars, journal editors, and academic…

Curriculum materials designed to provide students with practice interpreting plotted evidence of global climate change were developed using graphs from the scientific literature and tested with one hundred urban high school students from a high-poverty school in a major northern city in the US. The graph interpretation lessons followed a…

Responds to Biskin's comments (this issue) on the significance test controversy. Highlights areas of agreement (importance of replication evidence, importance of effect sizes) and disagreement (influence of sample size, evaluation of populations vs. samples, significance of Carver's article). Includes further recommendations for reporting research…

Significance tests are often used inappropriately in counseling research. In addition to comments on the significance test controversy (Vacha-Haase and Nilsson, this issue), a wider historical context and personal experiences are provided. The controversy is discussed, and seven recommendations for using significance tests are included. (EMK)

Discusses three topics related to interpretation of discriminant analyses (DA's): (1) partial F ratios and partial Wilks's lambdas for predictor variables in standard, step-down, and stepwise DA's; (2) relation of goals of classification to definition/evaluation of classification rules; and (3) significance tests for total hit rates in internal…