Chloe used a non-directional (two-tailed) hypothesis to investigate the relationship between daily caffeine consumption and anxiety levels.
She obtained the following data from a sample of 8 participants:
| Participant | Caffeine drinks per day | Rank 1 | Anxiety score (out of 10) | Rank 2 |
|---|---|---|---|---|
| A | 3 | 4 | 5 | 3.5 |
| B | 1 | 1.5 | 3 | 1.5 |
| C | 4 | 5.5 | 7 | 6 |
| D | 6 | 8 | 9 | 8 |
| E | 2 | 3 | 6 | 5 |
| F | 1 | 1.5 | 3 | 1.5 |
| G | 5 | 7 | 8 | 7 |
| H | 4 | 5.5 | 5 | 3.5 |
Chloe calculated a Spearman's rank correlation coefficient of rs=0.74r_s = 0.74rs=0.74.
An extract from the table of critical values for Spearman's rank correlation coefficient (rsr_srs) is shown below:
| NNN (Number of pairs) | p≤0.10p \le 0.10p≤0.10 (two-tailed) | p≤0.05p \le 0.05p≤0.05 (two-tailed) | p≤0.01p \le 0.01p≤0.01 (two-tailed) |
|---|---|---|---|
| 6 | 0.829 | 0.886 | 1.000 |
| 7 | 0.714 | 0.786 | 0.929 |
| 8 | 0.643 | 0.738 | 0.881 |
| 9 | 0.600 | 0.700 | 0.833 |
Explain whether Chloe's data were significant at p≤0.05 p \le 0.05\,p≤0.05 and if her research hypothesis should be accepted.
638 exam-style questions on Edexcel A Level Psychology Methods. Each one has a worked solution and a mark scheme showing where the marks go.