A health psychologist wanted to investigate whether a new sleep hygiene educational program was effective in reducing sleep disturbances for chronic insomnia sufferers. Eighteen participants completed the program. The researcher recorded the number of night-time awakenings each participant experienced in the week following the program and compared it to the week prior to the program.
Participants who had fewer awakenings in the week following the program than in the prior week were classified as 'Improved' (+). Participants who had more awakenings were classified as 'Deteriorated' (-). Participants who had the exact same number of awakenings were classified as 'Unchanged' (0).
Table 1
| Participant | Improved (+) | Deteriorated (-) | Unchanged (0) |
|---|---|---|---|
| 1 | + | ||
| 2 | - | ||
| 3 | + | ||
| 4 | 0 | ||
| 5 | + | ||
| 6 | + | ||
| 7 | - | ||
| 8 | + | ||
| 9 | + | ||
| 10 | - | ||
| 11 | 0 | ||
| 12 | + | ||
| 13 | + | ||
| 14 | - | ||
| 15 | + | ||
| 16 | + | ||
| 17 | - | ||
| 18 | + |
Calculate the sign test value of s s\,s for the data in Table 1. Explain how you reached your answer.
121 exam-style questions on AQA A Level Psychology Inferential testing (A-level only). Each one has a worked solution and a mark scheme showing where the marks go.