Suggest one psychological research question that could be answered by each of the following types of statistical tests:
z test
t test for independent samples, and
t test for dependent samples
Z-test:
Research question: Is there a significant difference in exam scores between students who received tutoring and students who did not receive tutoring?
To answer this question using a z-test, you would gather data on exam scores from two groups: students who received tutoring (group A) and students who did not receive tutoring (group B). Then, perform a z-test to compare the means of the two groups and determine if there is a statistically significant difference in their exam scores.
T-test for independent samples:
Research question: Does a new teaching method lead to improved reading comprehension compared to the traditional teaching method?
To answer this question using a t-test for independent samples, you would randomly assign participants to two groups: one group receiving the new teaching method and another group receiving the traditional teaching method. Then, measure their reading comprehension scores. Using a t-test, compare the means of the two groups to determine if there is a significant difference in reading comprehension between the two teaching methods.
T-test for dependent samples:
Research question: Is there a significant difference in anxiety levels before and after participating in a stress management program?
To answer this question using a t-test for dependent samples (also known as a paired samples t-test), you would measure anxiety levels of participants before they start a stress management program and after they have completed it. Each participant's anxiety levels would be treated as a pair of related data points. Perform a t-test on the paired scores to examine if there is a significant difference in anxiety levels before and after participating in the stress management program.