non-parametric analyses

Question 1

what is the non-parametric test used for the independent t-test?

Answer 1

Mann-Whitney

Question 2

what is the difference between the independent t-test and Mann-Whitney test?

Answer 2

parametric (independent t-test) = comparing MEANS of 2 independent groups, mann-whitney = comparing the MEAN RANKS of the 2 independent groups

Question 3

what would you expect the mann-whitney U to be if there is no difference between the mean ranks?

Answer 3

0

Question 4

what is the non-parametric test used for the paired t-test?

Answer 4

Wilcoxon signed-rank test

Question 5

what is the difference between the paired t-test and wilcoxon signed-rank test?

Answer 5

paired t-test = comparing means of 2 paired groups (within subjects), wilcoxon = comparing the mean ranks of the ppts who scored higher on condition 1 to the mean ranks of ppts who scored higher on condition 2

Question 6

what letter value is used for the wilcoxon test?

Answer 6

Z

Question 7

what is the non-parametric test used for Pearson’s R?

Answer 7

Spearman’s Rho

Question 8

what is the difference between Pearson’s r and spearman’s rho?

Answer 8

Pearson’s r investigates correlation between 2 continuous variables using EXACT scores, spearman’s rho investigates correlation between 2 continuous variables using RANKED scores

Question 9

what value is used for Spearman’s Rho?

Answer 9

rs

Question 10

what are the overall differences between parametric and non-parametric tests?

Answer 10

parametric: used when data is normally distributed, uses actual scores, more powerful and informative.

non-parametric: used when data is not normally distributed, uses rank data, less powerful