A psychologist develops a 30-item visual search test. Six adults complete the same test on two occasions, four weeks apart. The wording, room and time allowed are kept the same on both occasions.
| Participant | First score (out of 30) | Second score (out of 30) |
|---|---|---|
| A | 21 | 15 |
| B | 17 | 23 |
| C | 24 | 19 |
| D | 15 | 21 |
| E | 20 | 16 |
| F | 18 | 25 |
Which participant provides the strongest evidence that the test results were inconsistent across the two occasions? Give a reason for your answer.
Evaluate the reliability of this test. Use calculations based on the paired scores in your answer.
173 exam-style questions on OCR GCSE Psychology 7.3 Analysing Research, covering 7.3.1 Types of Data, 7.3.2 Measures of central tendency, 7.3.3 Other descriptive statistics, 7.3.4 Tables, Charts and Graphs, 7.3.5 Reliability, 7.3.6 Validity and effects on validity, and 7.3.7 Sources of bias. Each one has a worked solution and a mark scheme showing where the marks go.