Dr. Elena is a cognitive neuroscientist researching the impact of a high-intensity interval training (HIIT) session on working memory capacity. She conducts an experiment with 10 participants. Five participants are assigned to the control group (rested for 20 minutes) and five are assigned to the experimental HIIT group (completed a 20-minute HIIT session). At the end of the study, Dr. Elena records the number of errors made on a computerized N-back working memory task. She hypothesizes that participants in the HIIT group will exhibit fewer working memory errors than the control group.
Dr. Elena decides to perform a Mann-Whitney U U\,U test to find out whether the HIIT session has a significant effect on reducing cognitive errors. Table 4 shows the ranked results.
Complete Table 4 and calculate the Mann-Whitney U U\,U value for this data.
| Control Group | HIIT Group | ||
|---|---|---|---|
| Number of errors | Rank | Number of errors | Rank |
| 8 | 6.0 | 4 | 2.5 |
| 11 | 8.5 | 11 | 8.5 |
| 6 | 4.0 | 3 | 1.0 |
| 13 | 10.0 | 7 | 5.0 |
| 9 | 7.0 | 4 | 2.5 |
| Total | Total |
638 exam-style questions on Edexcel A Level Psychology Methods. Each one has a worked solution and a mark scheme showing where the marks go.