Problem Set 6 Multiple Attempts Not allowed. This Test can only be taken once. Force Completion This Test must be completed now. Question 1 What would be the most appropriate statistical test for a research project examining whether recidivism scores from 20 juveniles changed after participating in a cognitivebehavior program, in comparison to their scores prior to participating in the program? Answer t test for the correlation coefficient t test for dependent means t test for independent samples t test for related populations 10 points Question 2 For a t test for dependent means, how do you calculate the degrees of freedom? Answer 10 points Question 3 When do you use table B2? Answer At the beginning of the t test to set the level of risk to determine the critical t test value to determine the obtained t test value 10 points Question 4 Calculate the degrees of freedom. DF= Answer -9 10 20 9 10 points Question 5 Calculate the t value. t = Answer 7.80 77.80 -9.89 -5.90 10 points Question 6 Interpret your results at p < .05. Answer The null hypothesis must not be rejected. It can be concluded that there is no significant difference between the two sets of scores and the program was a failure. The null hypothesis must be rejected. It can be concluded that there is a significant difference between the two sets of scores and the program was successful. No interpretation of the results are possible because the obtained value is equal to .05. 10 points Question 7 How many subjects were there in the study? Answer can not be determined 59 50 56 10 points Question 8 The obtained t statistic was _______ and it was ________. Answer 1.13, not significant 1.13, significant 55, not significant .05, significant 10 points Question 9 In a two-tailed test, you would reject the null hypothesis Answer whenever there is a difference between the obtained t value and the critical value only if the difference between the obtained t value and the critical value is a negative number whenever the obtained t value is larger than the critical value whenever the critical value is 0 10 points Question 10 What is the difference between a t test for independent samples and a t test for dependent samples? Answer A t test for independent samples compares two unrelated groups, while a t test for dependent samples is used to compare scores from the same subjects under two different conditions. A t test for independent samples compares two related groups, while a t test for dependent samples is used to compare scores from the same subjects under the same conditions. There is no difference between the two. p < .05 in an independent sample and p > .05 in a dependent sample. 10 points