TESTS OF DIFFERENCE
1. Independent Samples T-Test: Used when comparing the means of two
independent or unrelated groups (e.g., a treatment group vs. a control
group). It tests the hypothesis that there is no difference in the population
means of the two groups.
2. Paired Samples T-Test: Used for comparing the means of two related
groups, such as the same group of participants measured at two
different times (e.g., before and after an intervention).
Non-Parametric Equivalents:
Non-parametric tests are used when the data do not meet the assumptions
required for parametric tests, such as normal distribution or when dealing
with ordinal data or ranks rather than interval or ratio data.
3. Mann-Whitney U Test: The non-parametric equivalent to the independent
samples t-test. It is used when comparing two independent groups and is
based on the ranks of the data
4. Wilcoxon Signed-Rank Test: The non-parametric counterpart to the
paired samples t-test. It is used for related or matched pairs of samples.