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) 40
- How 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?
Looking forward to your thoughts on these questions too!
