week 7 - Kruskal-Wallis test and Friedmans ANOVA

Question 1

what are the assumptions of normality

Answer 1

• very similar to with only two independent groups
• data in each group should follow a normal distribution

Question 2

what is the Kruskal-Wallis test

Answer 2

• alternative to the one-factor between-participant ANOVA
• appropriate if you have a design with three or more independent groups (no repeated measures)

Question 3

what is Friedmans ANOVA

Answer 3

• alternative to the one-factor within-participants ANOVA
• appropriate if you have a design with three or more repeated measures

Question 4

what is the theory of Friedmans ANOVA

Answer 4

• rank the data
• sum the ranks for each timepoint

Question 5

what is the theory behind the Kruskal-Wallis test

Answer 5

• order the dependent variable from smallest to largest
• rank the data
• sort back into original groups
• add up the ranks for each group
• use value to calculate the test stat (H)