A psychologist studying sleep and dreaming asks 30 first-year students aged 18 to 19 at one university in Japan to record whether they remember a dream on each of seven mornings. Twenty-four students remember at least one dream. The psychologist concludes that adults in all countries usually remember at least one dream each week.
In a study of psychological problems, another psychologist interviews adults about how frequently they experience panic symptoms. She predicts that most participants will report frequent symptoms. During the interviews, she smiles and nods when participants report frequent symptoms but looks down and moves to the next question when they report infrequent symptoms. Most participants report frequent panic symptoms.
Using the information above and your knowledge of bias, explain how far you agree with the claim that neither study can provide useful evidence.
In your answer, you should consider:
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.