A sports psychologist investigated whether listening to high-tempo music increases athletic endurance. Group X listened to electronic dance music (140 BPM140\text{ BPM}140 BPM) while running on a treadmill, and Group Y ran in silence. All participants performed the test in a temperature-controlled laboratory maintained at exactly 19∘C19^\circ\text{C}19∘C on identical treadmills with the same programmed incline profile.
| Participant: Group X (Music) | Endurance time (minutes) | Participant: Group Y (Silence) | Endurance time (minutes) |
|---|---|---|---|
| 1 | 24.5 | 1 | 21.0 |
| 2 | 31.0 | 2 | 25.5 |
| 3 | 28.5 | 3 | 20.0 |
| 4 | 35.0 | 4 | 28.0 |
| 5 | 22.0 | 5 | 23.5 |
| 6 | 29.5 | 6 | 19.5 |
Which extraneous variable has been controlled for in this research?
Participant baseline fitness level
Ambient room temperature of the testing environment
Type of running footwear worn by participants
Time of day of the test sessions
201 exam-style questions on OCR A Level Psychology Planning and conducting research. Each one has a worked solution and a mark scheme showing where the marks go.