Effect Sizes, Significance Tests, and Confidence Intervals: Assessing the Influence and Impact of Research Reporting Protocol and Practice
Degree Granting Department
Measurement and Evaluation
Jeffrey D. Kromrey, Ph.D
Kathryn M. Borman, Ph.D.
John M. Ferron, Ph.D.
Cynthia G. Parshall, Ph.D.
Research Practices, Practical Significance, Statistical Significance, Educational Research, Confidence Bands
This study addresses research reporting practices and protocols by bridging the gap from the theoretical and conceptual debates typically found in the literature with more realistic applications using data from published research. Specifically, the practice of using findings of statistical analysis as the primary, and often only, basis for results and conclusions of research is investigated through computing effect size and confidence intervals and considering how their use might impact the strength of inferences and conclusions reported.
Using a sample of published manuscripts from three peer-rviewed journals, central quantitative findings were expressed as dichotomous hypothesis test results, point estimates of effect sizes and confidence intervals. Studies using three different types of statistical analyses were considered for inclusion: t-tests, regression, and Analysis of Variance (ANOVA). The differences in the substantive interpretations of results from these accomplished and published studies were then examined as a function of these different analytical approaches. Both quantitative and qualitative techniques were used to examine the findings. General descriptive statistical techniques were employed to capture the magnitude of studies and analyses that might have different interpretations if althernative methods of reporting findings were used in addition to traditional tests of statistical signficance. Qualitative methods were then used to gain a sense of the impact on the wording used in the research conclusions of these other forms of reporting findings. It was discovered that tests of non-signficant results were more prone to need evidence of effect size than those of significant results. Regardless of tests of significance, the addition of information from confidence intervals tended to heavily impact the findings resulting from signficance tests.
The results were interpreted in terms of improving the reporting practices in applied research. Issues that were noted in this study relevant to the primary focus are discussed in general with implicaitons for future research. Recommendations are made regarding editorial and publishing practices, both for primary researchers and editors.
Scholar Commons Citation
Hess, Melinda Rae, "Effect Sizes, Significance Tests, and Confidence Intervals: Assessing the Influence and Impact of Research Reporting Protocol and Practice" (2003). USF Tampa Graduate Theses and Dissertations.