What Post hoc is
Post hoc (Latin for “after this”) is a statistical procedure used to compare the results of different treatments or conditions after an experiment or study has been conducted. It enables researchers to determine which treatments had the greatest effect and which did not.
Post hoc tests are used in an experimental setting to evaluate whether the differences between groups are statistically significant. The tests can be used to compare multiple groups to each other or to compare a single group to a control group.
Steps for Post Hoc:
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Determine the main research hypothesis that was tested in the experiment.
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Identify the levels of the independent and dependent variables.
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Calculate the means and standard deviations for each level of the independent variable.
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Determine the type of post hoc test to be used.
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Calculate the test statistic for each pairwise comparison.
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Set a significance level for the test.
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Compare the test statistic to the critical value.
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Interpret the results of the test.
Examples
- Using post hoc tests to compare the means of multiple groups after completing an ANOVA analysis.
- Carrying out post hoc tests to determine which specific groups differed from each other after completing a Kruskal-Wallis test.
- Utilizing post hoc tests to identify which pairs of means were significantly different after completing a Friedman test.