Background environment can significantly affect cognitive performance. A psychologist wanted to investigate whether background noise levels affect task efficiency. To test this, they set up an experiment where participants completed a complex spatio-visual puzzle.
One group of five participants completed the puzzle while typical background office noise (at 65 dB) was played. A different group of five participants completed the same puzzle in a completely quiet room (at 30 dB).
The time taken (in minutes) to successfully solve the puzzle was recorded. The data collected is presented in the table below.
| Time taken to complete the puzzle (minutes) | Quiet room group | ||||
|---|---|---|---|---|---|
| Background noise group | Quiet room group | ||||
| Participant | Score | Rank | Participant | Score | Rank |
| A | 12.5 | 4 | F | 10.2 | 1 |
| B | 14.0 | 6 | G | 11.5 | 2 |
| C | 16.5 | 8 | H | 12.0 | 3 |
| D | 19.0 | 10 | I | 13.5 | 5 |
| E | 18.2 | 9 | J | 15.0 | 7 |
| n1=5n_1 = 5n1=5 | n2=5n_2 = 5n2=5 |
Give one reason why the Mann-Whitney U test is the appropriate inferential test to use to analyse the data from this study.
644 exam-style questions on OCR A Level Psychology Research methods and techniques. Each one has a worked solution and a mark scheme showing where the marks go.