A sports psychologist investigates whether a new mindfulness technique reduces competitive anxiety in high-altitude climbers. Using a statistical test with a significance level of α=0.05\alpha = 0.05α=0.05, she finds a significant difference and rejects the null hypothesis. In reality, the mindfulness technique has no actual effect on anxiety levels.
Which of the following correctly identifies the type of error committed by the psychologist, and the probability of committing this error?
Type I error; probability is 0.050.050.05
Type I error; probability is 0.950.950.95
Type II error; probability is 0.050.050.05
Type II error; probability is 0.950.950.95
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.