1. Explain the difference between multiple independent variables and multiple levels of independent variables. Which is better?
2. What is blocking and how does it reduce "noise"? What is a disadvantage of blocking?
3. What is a factor? How can the use of factors benefit a design?
4. Explain main effects and interaction effects.
5. How does a covariate reduce noise?
6. Describe and explain three trade-offs present in experiments.