Non-parametric tests Flashcards
What are the assumptions of a parametric analysis?
- Data is (roughly) normally distributed
- There is homogeneity of variance
How do non-parametric tests work?
- Based on the principle of ranking the data
- Analysis is then carried out on the ranks rather than the actual data
What is the non-parametric equivalent for independent measures t-test?
Mann-whitney or wilcoxon rank-sum
What is the non-parametric equivalent for repeated measures t-test
Wilcoxon signed-rank
What is the non-parametric equivalent for a one-way independent ANOVA?
Kruskal-wallis
What is the non-parametric equivalent for a one-way repeated ANOVA?
Friedman’s
What do you need to test assumptions?
- Are your measurements data interval or ratio?
- Are they normally distributed?
- Is there homogeneity of variance?
Do normality tests need to be non-sig or sig?
sig = no normal distribution (non-parametric test needed)
What post-hoc test would you use for a repeated test?
Wilcoxon
What post-hoc test would you use for an independent test?
Mann-whitney