• Explain how a quasi-IV differs from an IV and the difference in language appropriate to use in a correlational versus an experimental study. Identify the IV (cause) and the DV (effect) in the following statement:

“The teenager’s back was peeling; she must have gotten sunburn.”

• In your own words, explain the difference between Type I and Type II errors.
   
• Explain why having sufficient power is important for a study. What are the four factors from Howell (2013) that affect the power of a research design? What is the most common way to increase power? In your own words, describe what an effect size is. How is power related to effect size?
   
• Of the threats to internal validity listed by Campbell and Stanley (1963), where do you have the most control? The least control? Give an example of a demand characteristic. What are the different role attitudes participants can have, according to Adair (1973)? What is the difference between a cover story and a manipulation check?
   
• Explain the difference between external validity and ecological validity.