Type of test | Dependent (outcome) variable (s) | Independent (explanatory) variable | Parametric Test (assumptions met) | Non-parametric (ordinal dependent or skewed) | Two independent variables of the same type |
---|---|---|---|---|---|
Test for a difference between two measurements of the same variable per subject | Continuous
Summary stats |
Time point (before/after) or condition | Paired t-test sheet | Wilcoxon signed rank sheet | Two-way repeated measures ANOVA or mixed between-within ANOVA if comparing groups |
Test for a difference 3+ measurements of the same variable e.g. three time points | Continuous | 3+ Time points or conditions | Repeated measures ANOVA | Freidman test | Two-way repeated measures ANOVA |
Comparison of two independent groups |
Continuous Summary stats |
2 different groups (binary) | Independent t-test video or sheet |
Mann-Whitney video or sheet |
Two-way ANOVA video 1 , part 2, part 3 |
Comparison of 3+ independent groups | Continuous Summary stats |
3+ different groups (nominal) | One way ANOVA ANOVA video or sheet, ANOVA assumptions | Kruskal-wallis video | Two-way ANOVA video 1 , part 2, part 3 |
Comparison of two or more independent groups | 2+ different groups | 2+ different groups | Chi-squared test & data summary video | Mann-Whitney (2 groups) or Kruskal-wallis (3+) | Logistic regression (DV:binary, IV:binary or continuous) |
Strength & significance of relationship | Continuous | Continuous (Correlation and scatterplot) | Simple linear regression video or sheet | Spearman's correlation but no regression alternative | Multiple linear regression video (IV:binary or continuous) |