Exam 20: Nonparametric and Resampling Statistical Tests

A Pediatrician wants to know if number of children in the family is related to how early parents arrive for regularly scheduled pediatric visits. The data follow in terms of the number of minutes early. Analyze and interpret the data using the Kruskal-Wallis procedure.

The Kruskal-Wallis test is appropriate when

If the null hypothesis is true and we run the Mann-Whitney test on our data, the expectation is that

When using Wilcoxon's matched pairs-signed ranks test, the rank of the difference between related scores is calculated.

In distribution-free tests, you usually reject the null hypothesis when the obtained value is smaller than the critical value.

One major argument promoting the use of parametric tests over distribution-free tests is that parametric tests are

A critic for the Food Network asked five world-renown chefs to taste three types of olive oil and rate them on a scale from 0 to 100 where 100 represents the highest quality. Analyze and interpret the following data using the Friedman test.

A teacher wanted to see if her students could complete a multiplication review sheet more quickly after practicing for a week. The total number of seconds it took each time are reported below. Calculate Wilcoxon's matched pairs signed ranks test on the following data and describe the results.

Distribution-free tests tend to be greatly affected by outliers.

When the assumptions behind parametric tests are not met,

Wilcoxon's test for paired samples focuses on

Tied scores often present a problem in distribution-free tests. The most common way to deal with them in a Mann-Whitney test is to

The Mann-Whitney test is used to compare the rank scores of two groups.

In the previous example of the smoking cessation study we might be tempted to apply Friedman's test, because it can handle similar data. This would be a bad idea because

In the previous question, the most appropriate test would be

Re-analyze the previous data using the normal approximation a. Calculate and interpret z . b. Which analysis is more appropriate? Explain.

Friedman's rank test for k-correlated samples is used to assess the degree of association between ranks, much like a correlation coefficient.

Under what conditions would you calculate in the Mann-Whitney test?

In a Kruskal-Wallis one-way analysis of variance, would you retain or reject the null hypothesis given the following information: a. H = 15.6, df = 8 b. H = 35.75, df = 25 c. H = 45.7, df = 30

Each of the distribution-free tests that are covered in the book deal with