Does the black grease beneath football players’ eyes really reduce

Does the black grease beneath football players’ eyes really reduce glare or does it just make them look intimidating? In a variation of a study actually conducted at Yale University, 46 participants placed one of three substances below their eyes: black grease, black antiglare stickers, or petroleum jelly. The researchers assessed eye glare using a contrast chart for each participant that gives a value on a scale measure. Every participant was assessed with each of the three substances, one at a time. Black grease led to a reduction in glare compared with the two other conditions, antiglare stickers or petroleum jelly (DeBroff & Pahk, 2003).

a. What is the independent variable? What are its levels?

b. What is the dependent variable?

c. What kind of ANOVA is this?

d. What is the first assumption for ANOVA? Is it likely that the researchers met this assumption? Explain your answer.

e. What is the second assumption for ANOVA? How could the researchers check to see if they had met this assumption? Be specific.

f. What is the third assumption for ANOVA? How could the researchers check to see if they had met this assumption? Be specific.

g. What is the fourth assumption, specific to the within-groups ANOVA? What would the researchers need to do to ensure that they meet this assumption?

h. Perform steps 5 and 6 of hypothesis testing. Be sure to complete the source table when calculating the F ratio for step 5.

i. If appropriate, calculate the Tukey HSD for all possible mean comparisons. Find the critical value of q and make a decision regarding the null hypothesis for each of the mean comparisons.

j. Calculate the R2 measure of effect size for this ANOVA.

k. How could this study be conducted using a between-groups design?

Find an article in the popular media (newspaper, magazine, Web

Find an article in the popular media (newspaper, magazine, Web site) that includes a graph in addition to the text.

a. Briefly summarize the main point of the article and graph.

b. What are the independent and dependent variables depicted in the graph? What kind of variables are they? If nominal, what are the levels?

c. What descriptive statistics are included in the article or on the graph?

d. In one or two sentences, what story is the graph (rather than the article) trying to tell?

e. How well do the text and graph match up? Are they telling the same story? Are they using the same terms? Explain.

f. Write a paragraph to the graph’s creator with advice for improving the graph. Be specific, citing the guidelines from this chapter.

g. Redo the graph, either by hand or by computer, in line with your suggestions.