Detailed Case,Theory & Numeric Problems-20 Questions - Sample Size, Effect Size, Power Analysis, Hypothesis & Non-Parametric Tests (Ex 13, JUS 302 Ch 9, t test, G*Power, ANOVA, SPSS, etc)

JUS 302

CHAPTER 9: HOMEWORK

NOTE: Please remember to restate the problem on your homework when submitting your answers.

1. Define “power” and “effect” and illustrate the relevance of each concept utilizing an original example. (1-2 paragraphs)

2. In 1-2 paragraphs describe when it is appropriate to set up your alternative hypothesis as a directional as opposed to a non-directional hypothesis.

3. An independent-measures research study uses two samples, each with n = 8 participants. If the data produce a t statistic of t = 2.10, what would your decision be with regard to your null hypothesis (i.e. reject, fail to reject). To get full credit for your answer you need to show how you got your critical value and describe your rationale for your final conclusion---i.e. [show calculation of critical value]; critical value is plus or minus 1.96, so we would fail to reject the null hypothesis because...).

Hint: you need to calculate the critical value based on the appropriate degrees of freedom; also, in evaluating the one tailed hypotheses, assume that the nature or direction of any difference you find is consistent with the alternative/research hypothesis).

a) For a two tailed hypothesis test (with alpha=.01)

b) For a one tailed hypothesis test (with alpha= .01)

c) For a two tailed hypothesis test (with alpha=.05)

d) For a one tailed hypothesis test (with alpha=.05) JUS 302

4. A psychologist has prepared an “Optimism Test” that is administered yearly to graduating college seniors. The test measures how each graduating class feels about its future (the higher the score, the more optimistic the class). Last year’s class had a mean score of  = 15. A sample of n = 9 seniors from this year’s class was selected and tested. The scores for these seniors are 7,12,11,15,7,8,15,9, and 6, which produce a sample mean of 10 with an estimated standard error of 1.14. Assume that you will use the .05 level of significance. For the two tailed test, your null hypothesis is that this year’s graduating class is equally optimistic about the future as last years’ graduating class; in other words there is no significant difference between last years graduating class and this years graduating class in terms of their level of optimism about the future. (NOTE: using symbols you can state the null in the following ways: Ho: =or  ≠for a two tailed test) For the one tailed test, your null hypothesis is that this year’s graduating class is equally or less optimistic about the future than last years’ graduating class or Ho:  ≤  or Ho:  ≤

a) State an appropriate non-directional alternative hypothesis (using symbols as well as words)

b) State an appropriate directional alternative hypothesis (using symbols as well as words)