Dr. Aris conducted an observational study to investigate whether the type of reinforcement used during maze navigation training in rats affected the learning strategy they developed. He recorded whether rats relied on a place strategy (using environmental landmarks) or a response strategy (using habit-based motor turns) after training with either a positive food reward or a negative thermal escape (getting out of cold water).
Table 1 shows the observed frequencies of Dr. Aris's study.
Table 1: Observed frequencies of learning strategies
| Reinforcement Type | Place Strategy | Response Strategy |
|---|---|---|
| Food Reward | 18 | 7 |
| Thermal Escape | 6 | 19 |
Complete Table 2 to calculate the chi-squared (χ2\chi^2χ2) statistic for Dr. Aris's observation. You must show your calculations and give your final answer to two decimal places.
Table 2: Chi-squared calculation table
| Reinforcement | Strategy | Observed (OOO) | Expected (EEE) | O−EO-EO−E | (O−E)2(O-E)^2(O−E)2 | (O−E)2E\displaystyle \frac{(O-E)^2}{E}E(O−E)2 |
|---|---|---|---|---|---|---|
| Food Reward | Place | 18 | 12.00 | |||
| Response | 7 | 13.00 | ||||
| Thermal Escape | Place | 6 | 12.00 | |||
| Response | 19 | 13.00 | ||||
| Chi-squared (χ2\chi^2χ2) = |
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.
