Ten visitors to an art gallery are asked to rate a Van Gogh painting alongside a sculpture each by Henry Moore and Michelangelo. What test would be used to see if there is a significant difference in ratings amongst the three pieces?
A) Mann-Whitney test
B) Signed-rank test
C) Friedman test
D) Kruskal-Wallis test

Question

Quizplus · Accepted Answer

The Friedman test is a non-parametric test used to compare three or more matched groups. In this case, the 10 visitors rated the three art pieces, making it a matched group design. The Mann-Whitney test and Signed-rank test are used to compare two independent groups and not appropriate for this scenario. The Kruskal-Wallis test is used to compare independent groups but is not appropriate for this scenario since the groups are matched. Therefore, the best choice for this scenario is the Friedman test.

Ten Visitors to an Art Gallery Are Asked to Rate