Positive Youth Development in the United States: Research Findings on Evaluations of Positive Youth Development Programs. Statistical Reporting

11/13/1998

Claims for the intervention based upon appropriate statistical analysis make it possible to have greater confidence in the conclusions about the intervention. These claims are more strongly supported when they include sufficient detail for the reader to make judgments regarding the significance of the findings. These data would include at a minimum:  the type of statistical test used, the test values generated (e.g., T or F values), the degrees of freedom, the sample size, and the p values (level of statistical significance). Ideally, evaluations would also include effect sizes or odds ratios to help the reader evaluate the strength of findings. While many of the programs reviewed did provide most of this information, they rarely included all of it. Typically even in strong evaluation reports, some statistics were not reported. An evaluation might list the numerical values for the several strongest findings, then simply provide narrative statements about the other results. While there are space limitations in many scientific journals, readers should be given the essential data necessary to determine the significance level, effect size, and power of the analyses presented in order to independently evaluate the importance of the findings to the field.