A researcher investigates whether team leaders interrupt team members more often during paired problem-solving discussions. Each discussion involves a different team leader and team member.
Before viewing the recordings, an observer is told that the researcher expects team leaders to interrupt more often. The observer records every occasion on which each person "cuts in", but this behaviour is not defined any further. The researcher first analyses 10 discussions and then increases the sample to 100 discussions. A second observer, who is not told the researcher's expectation, also watches the 100 discussions.
| Observer | Number of discussions | Mean interruptions by each team leader | Mean interruptions by each team member |
|---|---|---|---|
| Told the expectation | 10 | 6.8 | 3.1 |
| Told the expectation | 100 | 6.7 | 3.0 |
| Not told the expectation | 100 | 4.9 | 4.7 |
The researcher claims that increasing the sample from 10 to 100 discussions has removed the effect of bias.
Explain, using the data, why the researcher's claim is not justified and what conclusion should be drawn.
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.