1.How are related samples different from independent samples?

2.Name two research designs in which related samples are selected.

3. What are the assumptions for a related-samples t test?

4. For each example, state whether the one-sample, two-independent-sample, or related-samples t test is most appropriate. If it is a related-samples t test, indicate whether the test is a repeated-measures design or a matched-pairs

design.

a.A researcher matches right-handed and left-handed siblings to test whether right-handed siblings express greater emotional intelligence than left-handed siblings.

b.A professor tests whether students sitting in the front row score higher on an exam than students sitting in the back row.

c.A graduate student selects a sample of 25 participants to test whether the average time students attend to a task is greater than 30 minutes.

d.A principal at a local school wants to know how much students gain from being in an honors class. He gives students in an honors English class a test prior to the school year and again at the end of the school year to measure how much students learned during the year.

5. State the degrees of freedom and the type of test (repeated measures or

matched pairs) for the following examples of measures for a related-samples t test:

Time 1: 4, 3, 5, 4, 6

Time 2: 8, 2, 7,6, 3

a.The difference in coping ability in a sample of 20 brothers and sisters paired based on their relatedness

b.The difference in comprehension before and after an experimental training seminar in a sample of 30 students

c.The difference in relationship satisfaction in a sample of 25 pairs of married couples

d.The difference in athletic performance at the beginning and end of an athletic season for 12 athletes

6. A statistics tutor wants to assess whether her remedial tutoring has been effective for her five students. Using a pre-post design, she records the grades for a group of students prior to and after receiving her tutoring. The grades recorded are given in the table.

Tutoring

Before: 2.4, 2.5, 3.0, 2.9, 2.7

After: 3.0, 2.8, 3.5, 3.1, 3.5

a. Test whether or not her tutoring is effective at a .05 level of significance. State the value of the test statistic and the decision to retain or

reject the null hypothesis.

b. Compute effect size using estimated Cohen's d

7. A clinical psychologist noticed that the siblings of his obese patients are often not overweight. He hypothesized that the normal-weight siblings consume fewer daily calories than the obese patients. To test this using a matched-pairs design, he compared the daily caloric intake of obese patients to that of a matched

normal-weight sibling. The calories consumed for each sibling pair are given in the table.

Normal weight sibling: 1600, 1800, 2100, 1800, 2400, 2800, 1900, 2300, 2000, 2050

Overweight sibling: 2000, 2400, 2000, 3000, 2400, 1900, 2600, 2450, 2000, 1950

a.Test whether or not obese patients consumed significantly more calories than their normal-weight siblings at a .05 level of significance. State the value of the test statistic and the decision to retain or reject the null hypothesis.

b.Compute effect size using omega-squared.

c.Did the results support the researcher's hypothesis? Explain.