Chapter 07

Be able to use the z table to calculate percentiles and to find the percentage of scores in certain regions of the standard normal curve.

What is the z-test? When do we use it? Why do we use it?

What is the null hypothesis in a z-test? What is the alternative hypothesis?

Be able to recognize and use the formulas for zobt and for the standard error of the mean to conduct a z-test.

How do we interpret the result of our z test?

Define/understand sampling error.

What is the critical region/region of rejection? Understand the logic of this region.

What is the criterion for determining the region of rejection in a z test?

What is a one-tailed test? What is a two-tailed test? When do we use each one?

If alpha = .05, what is zcrit (critical z) for a one-tailed test? For a two-tailed test?

What do we do when a z test result is in the region of rejection? What does that mean? Understand the logic of what it means.

What does it mean when our results in a z-test are “significant”? Have we proved that the sample did not come from the population? Why or why not?

What are HARKing and p-hacking? What are the ethical problems with these?


Be able to perform and interpret any SPSS procedures that we do for this chapter.