## Multiple choice questions

A researcher measured people’s physiological reactions while watching a horror film and compared them to when watching a comedy film, and a documentary about wildlife. Different people viewed each type of film. The resulting data were normally distributed and the variances across groups were similar. What test should be used to analyse the data?

1. Repeated-measures analysis of variance
2. Kruskal–Wallis test
3. Friedman’s ANOVA
4. Independent analysis of variance

#### Answer: Independent analysis of variance

When variances across independent groups are unequal, which of the following is not an appropriate course of action.

1. Use Games–Howell post hoc tests.
2. Use Kruskal–Wallis test.
3. Use Welch’s F-ratio.
4. Use Friedman’s ANOVA.

Which of these statements describes a Bonferroni correction?

1. You apply a criterion for significance based on the usual criterion for significance (.05) divided by the number of tests performed.
2. You divide the F-ratio by the number of tests performed.
3. The degrees of freedom are corrected to make the F-ratio less significant.
4. The error in the model is adjusted for the number of tests performed.

#### Answer: You apply a criterion for significance based on the usual criterion for significance (.05) divided by the number of tests performed

Levene's test tests whether:

1. Data are normally distributed.
2. The variances in different groups are equal.
3. The assumption of sphericity has been met.
4. Group means differ.

#### Answer: The variances in different groups are equal

Which of the following is not a type of post hoc test?