Use the preparation materials to prepare hand-written answers for the following questions. Please ask any questions on the "Questions -- Preparation Guide" on the course Team (see link on the homepage.)
  1. What are the four assumptions of a One-Way ANOVA?
  2. Which two assumptions are critical for a One-Way ANOVA and which one is the One-Way ANOVA resilient to?
  3. What are the five most common transformations (by name and by power value)?
  4. Which of those five transformations is “strongest” (i.e., handles the most skewed data)?
  5. Which of those five transformations is the transformation that you should try first and that you hope works (relative to the other transformations)? Why?
  6. Explain how a log transformation can “transform” a strongly right-skewed to a symmetric distribution.
  7. Is it possible to use a power transformation with data that contains negative values? Explain how?
  8. Explain how you will use R to find an appropriate power transformation for meeting the assumptions of a One-Way ANOVA.
  9. What transformation is used most often if the response variable consists of percentages?
  10. How do you back-transform the mean log of Y to be just the mean of Y?
  11. How do you back-transform the mean fourth root of Y to be just the mean of Y?
  12. Can you back-transform the difference in group means of the cube root of Y?
  13. Can you back-transform the difference in group means of the log of Y?
  14. How do you interpret the back-transformed difference in group means of the log of Y?