A cognitive psychologist investigated whether inhaling peppermint essential oil during study increases memory recall. Table 1 shows the memory recall test scores (out of 15) of 10 participants measured before and after inhaling the peppermint oil.
| Participant | Recall score before | Recall score after |
|---|---|---|
| Participant A | 8 | 11 |
| Participant B | 10 | 10 |
| Participant C | 7 | 9 |
| Participant D | 12 | 14 |
| Participant E | 9 | 9 |
| Participant F | 6 | 11 |
| Participant G | 11 | 13 |
| Participant H | 13 | 10 |
| Participant I | 5 | 8 |
| Participant J | 10 | 12 |
When using a Wilcoxon Signed-Ranks Test to analyze the difference, the calculated value of T T\,T was found to be 6 (T=6T = 6T=6).
| NNN | p≤0.05p \le 0.05p≤0.05 (one-tailed) | p≤0.05p \le 0.05p≤0.05 (two-tailed) |
|---|---|---|
| 7 | 3 | 2 |
| 8 | 5 | 3 |
| 9 | 8 | 5 |
| 10 | 11 | 8 |
Using the data in Table 1 and Table 2, explain whether the results are significant at p≤0.05 p \le 0.05\,p≤0.05 for a directional (one-tailed) hypothesis, and if the researcher's directional hypothesis can be accepted.
Practise Edexcel A Level Psychology Methods with exam-style questions for A Level Psychology. 638 questions, 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.