A psychologist investigated whether background music affects cognitive performance. Two groups of six participants solved logic puzzles for 10 minutes. Group 1 listened to instrumental background music, while Group 2 worked in silence. The number of puzzles correctly solved by each participant (out of 20) is presented in the table below.
| Number of puzzles correctly solved (max. 20) | |||||
|---|---|---|---|---|---|
| Instrumental music group | Silence group | ||||
| Participant | Score | Rank | Participant | Score | Rank |
| a | 14 | 5 | a | 8 | 1 |
| b | 15 | 6.5 | b | 10 | 2 |
| c | 16 | 8 | c | 11 | 3 |
| d | 17 | 9 | d | 13 | 4 |
| e | 18 | 10 | e | 15 | 6.5 |
| f | 19 | 11 | f | 20 | 12 |
| n1=6n_1 = 6n1=6 | n2=6n_2 = 6n2=6 |
Before conducting a Mann-Whitney U test, the data from both groups must be pooled and ranked.
In the results, two participants have the same score of 15. Explain how this is dealt with when ranking the data.
513 exam-style questions on OCR A Level Psychology Data recording, analysis and presentation. Each one has a worked solution and a mark scheme showing where the marks go.