Here are the questions for Chapter 9’s food for thought:

 What is a between subjects design?  How does this differ from within subjects?Define a two-independent sample t-test.  What are the assumptions associated with a two-independent sample t-test?A researcher measures the time it takes 13 men and 15 women to complete multiple tasks in a study. She compares the mean difference between men and women using the two-independent-sample t test. What is the critical value for this test if she conducts a two-tailed test at a .05 level of significance?What is the denominator for computing an estimated Cohen’s d for a two-independent-sample t test?If the difference between two means is 4, then what will the estimated Cohen’s d value be with a pooled sample standard deviation of each of the following? (a)   4 (b)   8 (c)   16 (d)   40How do you calculate the degrees of freedom for a 2-independent sample t-test?What is the pooled sample variance?  Pooled sample standard deviation? When an independent sample is selected, are the same or different participants observed in each group? Name three measures used to estimate effect size for the two-independent-sample t test.What are the three steps to compute an estimation formula?  In the following studies, state whether you would use a one-sample t test or a two-independent-sample t test. (a)    A study measuring differences in attitudes about morality among men and women (b)    A study testing whether night-shift workers sleep the recommended 8 hours per day (c)    An experiment measuring differences in brain activity among rats placed on either a continuous or an intermittent reward schedule.Will each of the following increase, decrease, or have no effect on the value of the test statistic for a two-independent-sample t test? (a)    The total sample size is increased. (b)    The level of significance is reduced from .05 to .01. (c)    The pooled sample variance is doubled.When is the t-test for independent means appropriate to use?How should the t value be interpreted?  How do we know what it means?  For example, when t(28) = -0.16, p. n.s. – what does this mean?