A psychologist conducts an experiment to investigate whether a new mnemonic technique improves word recall compared to a control group. Because the data is ordinal and an independent groups design is used, the psychologist performs a Mann-Whitney U U\,U test. For a directional hypothesis at the 5% significance level (p≤0.05p \le 0.05p≤0.05), the critical value of U U\,U is 18. The calculated observed value of U U\,U is 15.
Which of the following is the correct conclusion and justification for this test?
The result is significant because the observed value of UUU (151515) is less than or equal to the critical value (181818).
The result is not significant because the observed value of UUU (151515) must be greater than or equal to the critical value (181818) to reject the null hypothesis.
The result is significant because the critical value (181818) exceeds the standard significance level of 0.050.050.05.
The result is not significant because the observed value of UUU (151515) is greater than the significance level of 0.050.050.05.
644 exam-style questions on OCR A Level Psychology Research methods and techniques. Each one has a worked solution and a mark scheme showing where the marks go.