A researcher was interested in depression levels of patients during treatment. She took the same group of 8 patients and measured their depression (out of 15) before treatment and again during treatment. The data were not normally distributed. Which test should she use to compare her experimental conditions?

Select one:

a. Paired samples t-test

b. Wilcoxon signed-rank test

c. Mann-Whitney test

d. Wilcoxon rank-sum test

Which of the following tests would you use to assess whether there is a significant difference between the mean ranks of two conditions?

Select one:

a. Friedman's ANOVA

b. Mann-Whitney Test

c. Wilcoxon Signed Rank Test

d. Kruskal-Wallis Test

parametric tests, unlike the nonparametric tests, make certain assumptions about

Select one:

a. the population size

b. the underlying distribution

c. the sample size

d. the null hypothesis