Practical significance of non-parametric results: contributions to “Satisfaction and body mass index and its influence on physical self-concept”
e202001011
Keywords:
Body mass index, Physical self-conceptAbstract
In a recent study on physical self-concept, results were reported on its variability with respect to satisfaction and body mass index. One of the methodological successes of the study was the inclusion in Table 2 of the strength of the relationship between the variables analyzed, expressed by Cramer's V coefficient. But this reference was inconsistent and limits the information that can be extracted from the study. Specifically, the null hypothesis results in Tables 3 and 4 would gain more interpretive content if an estimate of the magnitude or size of the differences, something commonly known as practical significance, were included.
Practical significance can be estimated for the size or magnitude of the differences between groups or the relationships between variables studied. Given that in areas of science as heterogeneous as physical anthropology, bone surgery, epidemiology, localized pediatrics or learning problems, there is still an insistence on moderating the use of statistical significance tests as the substantial element to interpret The importance of the results, the practical significance in Fernandez's results must be strengthened. For this reason, this letter complements the results of tables 3 and 4 of said article by using two estimators applied to the results of the Kruskal-Wallis test: eta2 and epsilon2. Both are interpreted as correlational coefficients, specifically as shared variance between the two related variables. Applicable effect size estimates for nonparametric tests generally take the form of explained variance or squared correlations.
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