| Question 1: Various publications have found a higher than expected incidence of p-values immediately below p=0.05 as compared to p-values immediately above p=0.05. Some possible reasons for this over-representation could include: |
| Reference: | B. Ginsel, et al., The distribution of probability values in medical abstracts: an observational study., BMC Res Notes, Nov 26, 2015. |
| Choice A: | Publication bias. |
| Choice B: | Statistical fraud. |
| Choice C: | Methodological errors (selective reporting, selective analyses, underpowered analysis). |
| Choice D: | A and C. |
| Choice E: | All of the above. |
| Question 2: A p-value can best be described as the probability, under a specified statistical model, that: |
| Reference: | R.L. Wasserstein and N.A. Lazar, The ASA’s statement on p-values, context, process, and purpose, The American Statistician, accepted version published online 3/7/2016. |
| Choice A: | The null hypothesis is true. |
| Choice B: | A statistical summary of the data would be equal to or more extreme than its observed value. |
| Choice C: | The statistical summary of the data was a random coincidence unique to the given data under analysis. |
| Choice D: | The results would not hold up if the experiment is repeated. |
| Choice E: | The data has sufficient statistical power to detect a given effect. |
| Question 3: Effect sizes are more important than p-values because: |
| Reference: | H. Motulsky, Intuitive Biostatistics: A nonmathematical guide to statistical thinking, Oxford Univ Press, (2014), pp. 133-134. |
| Choice A: | They are unitless measures. |
| Choice B: | They are sample independent. |
| Choice C: | They tell you how practically meaningful your results are. |
| Choice D: | They are unrelated to the p-value. |
| Question 4: True or False: The ½ standard deviation method is an accepted criterion for determining clinical significance in quality of life (QOL) studies? |
| Reference: | J. Sloan, et al., “Clinical significance of patient-reported questionnaire data: another step towards consensus”, J. Clinical Epidemiology 58, 2005. |
| Choice A: | True. |
| Choice B: | False. |
| Question 5: What does a high R2 value mean for a simple linear regression model? |
| Reference: | An introduction to categorical data analysis 2nd edition. Alan Agresti, John Wiley and Sons, Inc. Hoboken, NJ 2007; p. 144. |
| Choice A: | The model accounts for a lot of the data variability . |
| Choice B: | The null hypothesis should be rejected. |
| Choice C: | The data is linear with a positive slope. |
| Choice D: | There are no outliers in the data. |
| Question 6: A researcher collects a database of T2W MR cases demonstrating glioblastoma. He wants to compare tumor area between manual outlines and a new computer algorithm. The most appropriate test would be: |
| Reference: | Bland and Altman, “Statistical methods for assessing agreement between two methods of clinical measurement,” Lancet 327, 307 (1986). |
| Choice A: | Pearson Correlation. |
| Choice B: | Spearman Correlation. |
| Choice C: | Fleiss’ Kappa. |
| Choice D: | Bland-Altman Analysis. |
