Indicate whether each of the following studies involves two independent samples or two related samples, and in the latter case, indicate whether the study involves repeated measures of the same subjects or matched pairs of different subjects.

1. Intelligence test scores of a group of precocious children at age 8 and at age 12.

2. Communication skills of men compared with those of women.

3. Memory test scores of fourth graders on a task of learning information about unfamiliar cities compared to their memory test scores on a task of learning information about familiar cities.

4. Hours of weekly exercise of wives compared to hours of weekly exercise of their husbands.

5. Graduate Record Exam (GRE) scores of college students matched on grade point average and then randomly assigned to a GRE training condition or to a control condition.

6. Verbal ability test scores of identical twins.

7. Problem solving skills of chess players compared to problem solving skills of bridge players.

8. Grade point averages of swimmers compared to grade point averages of tennis players.

9. Weight of participants before they begin a weight management program and again at the end of the program.