When can a t-test be done more than once in the same study?
- When to do a paired t-test instead of an ANOVA?
- If I am measuring levels of happiness, depression, and anxiety in the same group of participants before and after they exercise,
what type of statistical analysis do I use?
A t-test can be done more than once in the same study when you have multiple independent variables or when you want to compare multiple pairs of groups.
A paired t-test is typically used when you have two related measurements or when you want to compare the means of two dependent groups. On the other hand, an ANOVA (Analysis of Variance) is used when you have more than two groups and want to compare their means.
In the scenario of measuring levels of happiness, depression, and anxiety in the same group of participants before and after they exercise, you would typically use a repeated measures ANOVA or a paired t-test. The choice between the two will depend on the specific research question and the assumptions of the statistical tests. The repeated measures ANOVA would be suitable if you want to compare the means of all three variables across two time points, considering the potential interactions between the variables. A paired t-test, on the other hand, would be appropriate if you are interested in examining the differences specifically within the pairs of variables (e.g., happiness before vs. after exercise, depression before vs. after exercise, and anxiety before vs. after exercise) separately.