When a researcher retains a null hypothesis that is actually false, which type of error has been committed?
a Type 1 error
a Type 2 error
both a Type 1 and a Type 2 error
neither a Type 1 nor a Type 2 error
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.