Reminder about error types:

• Type I Error: You find a difference but in reality you should not have found a difference
• Type II Error: You did not find a difference but in reality you should have found a difference

For the studies below, discuss what probability level you would useand why.Remember that your probability level should always be selected BEFORE you collect your data or compute your statistic. Assess the risk of Type I and Type II error.Remember that when we say "risk" here, we're referring to how problematic an error type would be. Would lives be lost if we committed a Type I or Type II error? Would it cost anyone a lot of money? (More onWeek 5: Instructor Lecture 1.9: How to Select a Probability Level)

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to guide your decision.

Research Study 1: Researchers are going to test the effectiveness of a new blood pressure medication. What probability level should they use in this research?

Research Study 2: Researchers are studying differences between men and women on various mathematical skills. What probability level should they use in the research?

Research Study 3: Researchers are testing out a new medication aimed at halting the cognitive declines caused by Alzheimer's disease (currently no such treatment is available). What probability level should they use in the research?

Research Study 4: Researchers are testing out the benefits of a new herbal treatment for the treatment of menopausal symptoms in women. Note that the new herbal treatment is relatively expensive (approximately $100/month).

Research Study 5: Researchers are examining the effects of tryptophan-free (tryptophan is a precursor to serotonin) diet on predatory aggression in rats.

Research Study 6: Researchers are examining the differences between older and younger adults on the impact of glare on vision.