A researcher conducted a laboratory experiment to investigate the effect of ambient lighting on reaction time during a simulated night-driving task. One group of participants completed the task under blue-enriched white light, while another group completed the same task under warm yellow light.
| Blue-Enriched Light | Warm Yellow Light | ||
|---|---|---|---|
| Participant | Reaction Time (ms) | Participant | Reaction Time (ms) |
| Participant A | 240 | Participant F | 285 |
| Participant B | 255 | Participant G | 290 |
| Participant C | 230 | Participant H | 310 |
| Participant D | 248 | Participant I | 295 |
| Participant E | 262 | Participant J | 302 |
Which of the following would act as an extraneous variable in this study?
Ambient lighting color
Hair color
Sleep duration the night before
Shoe size
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.