Ackerman and Goldsmith (2011) report that students who study from a screen (smartphone, tablet, or computer) tended to have lower quiz scores than students who studied the same material from printed pages. To test this finding, a professor identifies a sample of n = 16 students who used the electronic version of the course textbook and determines that this sample had an average score of M = 72.5 on the final exam. During the previous three years, the final exam scores for the general population of students taking the course averaged = 77 with a standard deviation of = 8 and formed a roughly normal distribution. The professor would like to use the sample to determine whether students studying from an electronic screen had exam scores that are significantly different from those for the general population.

	Answers	Possible points
What is the independent variable?		0.50
What is the dependent variable?		0.50
Is the value 72.5 a statistic or a parameter?		0.50

Using the standard hypothesis testing process, conduct a two-tailed hypothesis test with = .05 to evaluate the effect of studying from an electronic screen. Also compute Cohen's d to estimate the effect size.

Answer (4 points)

Based on your decision to the final step of the hypotheses test what type of error might you be making?

Answer	Possible points
	0.50

For the above question compute and interpret Cohen's d to estimate the effect size.

	Answer	Possible points
Compute Cohen's d		0.50
Interpret Cohen's d		0.50