Question

1. Below are several research scenarios. Indicate which set of statistical analyses should be used to analyze the data collected in study, and explain why that statistical test should be used

(c) A researcher developed a video designed to enhance creative writing. Fifty high school students were asked to participate in the study. Twenty-five were randomly assigned to group A and the other twenty-five were assigned to group B. The video was shown to group A, and group B read a short story by Mark Twain. Both groups knew they were participating in an experiment, and both groups also knew that group A was the experimental group. After receiving their treatments, both groups were asked to write an essay on anything they chose. Next three English teachers read each and every essay and provided a creativity score for the essay ranging from a low of one to a high of ten.

Answer 1

Students will be given numbers from 1 to 10 that is some sort of ranking. So, we can apply the procedures which are applicable to the data involving ranking.

In that,

we can have the Mann–Whitney U-test which is a non-parametric test of the null hypothesis that two populations are the same against an alternative hypothesis, that a particular population tends to have larger values than the other.

In case of ties (which are more likely to happen in this data), he Wilcoxon signed-rank t-test is useful.

We can also find Spearman's rank correlation between these two groups.