Dr. Aris conducted a field experiment in a public park to investigate whether people are more likely to obey a directive to pick up a discarded plastic bottle depending on the authority of the person making the request. He used two conditions: in the first, a confederate was dressed in a park ranger's official uniform; in the second, the same confederate was dressed in a plain grey tracksuit.
The confederate approached lone park visitors and said, "Pick up that bottle and throw it in the bin."
Dr. Aris recorded the number of visitors who obeyed the instruction and those who refused in each condition. The results are shown in Table 1.
| Confederate in park ranger uniform | Confederate in plain grey tracksuit | |
|---|---|---|
| Obeyed and disposed of the litter | 22 | 8 |
| Refused to dispose of the litter | 10 | 26 |
Explain one improvement that could be made to the experimental design used in Dr. Aris's research.
Practise Edexcel A Level Psychology Research methods and skills with exam-style questions for A Level Psychology. 657 questions covering Research methods and skills, matched to the Edexcel A Level Psychology (9PS0) specification and written in Paper 1, Paper 2 and Paper 3 style. Every question includes a full worked solution and mark scheme, so you can see where marks are awarded rather than just whether you got the answer right.
