PSYC60 EXAM 2 STUDY GUIDE 1. 2. 3. 4. 5. 6. 7. 8. 9. 10. 11. 12. 13. 14. 15. 16. 17. 18. 19. 20. 21. 22. 23. 24. 25. 26. 27. 28. 29. What is a standard error? How does it relate to a standard deviation? What does a z for a sample mean represent? How does a z differ from a t? What is the difference between and s? How do you calculate the standard error of the mean (i.e. a single mean) if you know ? How do you calculate the standard error of the mean if you don't know ? What is the effect of n on the standard error of the mean? What is a null hypothesis? What is an alternative hypothesis? Why are hypotheses written in terms of population parameters and not sample statistics? If the null hypothesis is true, what percent of sample means will fall within +/- 1.96 standard errors of the mean? What percent will fall within +/- 2 standard errors of the mean? What percent will fall within +/- 2.58 standard errors and between +/- 3.30 standard errors? If the null hypothesis is true, what percent of sample means will be greater than 1.96 standard errors of the mean? What percent will be lower than 1.96 standard errors? What does alpha refer to? When doing hypothesis testing, why do researchers typically use alphas of .05, .01, or .001? What is a Type I error, and how does it relate to the alpha level? What is a Type II error, and how does it relate to a Type I error? How do I decrease my probability of making a Type I error? When I decrease my probability of making a Type I error, what happens to my probability of making a Type II error? How can I decrease Type I and Type II errors simultaneously? What does it mean to say that a result is \"statistically significant\"? What does it mean to say that a result is \"not significant\"? What are the assumptions of a single sample z-test? What are some examples of violations of each of the assumptions? Why is it important to evaluate \"practical significance\" in addition to \"statistical significance\"? What does Cohen's d assess? What are the cutoffs for \"small\