A health psychologist wanted to see if a simple visual nudge would increase hand sanitizer use at a local clinic. They monitored the use of two identical sanitizer dispensers placed near the main entrance: one with bright green footprints painted on the floor leading towards it, and one without any markings. They recorded the status of each person who used the dispensers over a three-hour period.
The table below shows the distribution of users:
| Healthcare Workers | Public Visitors | |
|---|---|---|
| Dispenser with footprints | 32 | 18 |
| Dispenser without footprints | 15 | 20 |
The psychologist analysed the data using a Chi-square test and obtained a calculated value of χ2=4.15\chi^2 = 4.15χ2=4.15.
Below is an extract from the table of critical values for the Chi-square test:
| Degrees of Freedom (dfdfdf) | p=0.10p = 0.10p=0.10 | p=0.05p = 0.05p=0.05 | p=0.01p = 0.01p=0.01 |
|---|---|---|---|
| 1 | 2.71 | 3.84 | 6.63 |
| 2 | 4.61 | 5.99 | 9.21 |
Write a significance statement presenting this finding, showing whether the results are significant or not at the 5% level of probability (p≤0.05p \le 0.05p≤0.05).
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.