A neuropsychologist measures the relationship between hours of sleep deprivation and performance on a cognitive processing task across four different experimental groups, obtaining the following correlation coefficients (rrr):
Which of these correlation coefficients indicates the weakest relationship between sleep deprivation and cognitive performance?
−0.91-0.91−0.91
−0.15-0.15−0.15
+0.08+0.08+0.08
+0.87+0.87+0.87
513 exam-style questions on OCR A Level Psychology Data recording, analysis and presentation. Each one has a worked solution and a mark scheme showing where the marks go.