A clinic has four doctors.They wish to compare the amount of time that doctors spend with their patients.It is suspected that times may not be normally distributed but are otherwise assumed similar except in center,so a nonparametric test was chosen.The Kruskal-Wallis test results are shown below. Which is the best conclusion?
A) The doctors have the same median times at α = .01.
B) The doctors have different median times at α = .01.
C) The sample size is insufficient for this kind of test.
D) A one-factor ANOVA would be a better kind of test.

Question

A clinic has four doctors.They wish to compare the amount of time that doctors spend with their patients.It is suspected that times may not be normally distributed but are otherwise assumed similar except in center,so a nonparametric test was chosen.The Kruskal-Wallis test results are shown below.  Which is the best conclusion?
A) The doctors have the same median times at α = .01. 
B) The doctors have different median times at α = .01. 
C) The sample size is insufficient for this kind of test. 
D) A one-factor ANOVA would be a better kind of test.

Quizplus · Accepted Answer

The Kruskal-Wallis test is a nonparametric test for comparing the medians of multiple groups. The test result shows a p-value of 0.008, which is less than the significance level of 0.01. Therefore, we reject the null hypothesis of equal medians and conclude that the doctors have different median times spent with their patients at α = .01. Choice A is incorrect because the conclusion is not that they have the same median times. Choice C is incorrect because we have sufficient sample size. Choice D is incorrect because the Kruskal-Wallis test is the appropriate nonparametric test for this situation, and ANOVA requires normality assumption.

A Clinic Has Four Doctors