Behavioral researchers often use statistical techniques to support conclusions about behavioral differences between particular groups of people and the general population of people. This approach has been useful, for example, in identifying memory decrements that result from head injuries. One such study observed participants with lesions in the frontal lobe of the brain, which is thought to be involved in memory functions, and compared their performance on a simple recall task to established norms on the task to see if memory performance was reduced. The normative (general population) data for the task was normally distributed. The researcher measured the performance of 24 people in the sample being studied and compared their scores to the normative data, using an alpha value of .05.
1) State the null and alternative hypotheses, both in words and in symbols.
2) Under the conditions described in the scenario, what statistical test would be appropriate? Explain the rationale for your answer.
3) Would it be most appropriate to use a two-tailed test, a left-tailed test, or a right-tailed test? Why?
4) In one paragraph, describe the conclusion you would reach about the participants' performance if the P-value of the hypothesis test was determined to be .035. Include the rationale for your conclusion.