A Level Psychology OCR Practice Exam

For testing differences using repeated measures with ordinal or continuous data, which statistical test is most suitable?

1. T-Test

2. Mann-Whitney test

3. Wilcoxon test

4. ANOVA

The correct answer is: Wilcoxon test

The Wilcoxon test is the most suitable statistical test for assessing differences when using repeated measures with ordinal or continuous data, particularly when the data does not meet the assumptions required for parametric tests like t-tests or ANOVA. This test is specifically designed for situations where the same subjects are tested under different conditions or at different times, making it appropriate for repeated measures designs. It evaluates the differences between paired observations by ranking the differences for the matched pairs rather than assuming a normal distribution of the data. The Wilcoxon test effectively accounts for the non-paramatric nature of ordinal data and is robust when working with continuous data that may not conform to the assumptions of typical parametric tests. This unique characteristic allows researchers to extract meaningful insights from their data without compromising validity due to distributional assumptions. In contrast, the other methods listed are less suitable in this context. The t-test is generally used for independent samples unless paired differences are examined; the Mann-Whitney test is designed for independent groups; while ANOVA is more appropriate for comparing means across three or more groups or conditions rather than the repeated measures of the same subjects. Therefore, the Wilcoxon test stands out as the best choice for the scenario described.