Dr. Aris is a clinical psychologist researching the effectiveness of a new digital mindfulness therapy app on reducing anxiety in young adults. He conducts an experiment using 10 participants recruited from a local clinic. Five participants are assigned to the control group (no app) and five are assigned to the experimental group (completed 2 weeks of the digital therapy app). At the end of the study, Dr. Aris records the number of self-reported anxious symptoms experienced during a public-speaking task. He hypothesizes that participants using the therapy app will exhibit fewer anxious symptoms than the control group.
Dr. Aris decides to perform a Mann-Whitney U test to find out whether the therapy app has a significant effect on reducing anxious symptoms. Table 4 shows the ranked results.
Complete Table 4 and calculate the Mann-Whitney U value for this data.
| Control Group | Experimental Group | ||
|---|---|---|---|
| Number of anxious symptoms | Rank | Number of anxious symptoms | Rank |
| 12 | 7.5 | 8 | 3.0 |
| 10 | 5.5 | 12 | 7.5 |
| 15 | 10.0 | 6 | 2.0 |
| 10 | 5.5 | 9 | 4.0 |
| 14 | 9.0 | 5 | 1.0 |
| 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.