Across one working week, a psychologist collects paired measurements from 64 employees in an insurance office. For each employee, she records the mean background noise level at their desk in decibels and obtains the percentage of claim forms they entered accurately from the office's routine audit records. The results show a zero correlation. The office director concludes that reducing background noise would not improve employees' accuracy.
Evaluate the use of a correlation in this investigation.
139 exam-style questions on OCR GCSE Psychology 7.2 Doing Research, covering 7.2.1 Experiments, 7.2.2 Interviews, 7.2.3 Questionnaires (Surveys), 7.2.4 Observations, 7.2.5 Case Studies, and 7.2.6 Correlations. Each one has a worked solution and a mark scheme showing where the marks go.