State whether each of the following is an example of a repeated-measures design or a matched-samples design

State whether each of the following is an example of a repeated-measures design or a matched-samples design.

1. Researchers measure the number of unforced errors committed by a sample of professional tennis players during each set of a tennis match.

2. Researchers record the amount of time (in minutes) that parent-child pairs spend on social networking sites to test for generational differences between the pairs.

3. Researchers compare perceptions of safety in four different social settings among pairs of participants matched based on emotional stability scores.

4. Name the test statistic used to compare differences between two group means using a within-subjects design. Name the test statistic used to compare differences among two or more group means using a within-subjects design.