Have you ever wondered whether soccer players suffer adverse effects from hitting “headers”? The authors of the article “No Evidence of Impaired Neurocognitive Performance in Collegiate Soccer Players” (Amer. J. of Sports Med., 2002: 157–162) investigated this issue from several perspectives.

a. The paper reported that 45 of the 91 soccer players in their sample had suffered at least one concussion, 28 of 96 nonsoccer athletes had suffered at least one concussion, and only 8 of 53 student controls had suffered at least one concussion. Analyze this data and draw appropriate conclusions.

b. For the soccer players, the sample correlation coefficient calculated from the values of soccer exposure (total number of competitive seasons played prior to enrollment in the study) and score on an y 5 x 5 Pij 5 .5 1 .2813625 (zi 2 zj

)

immediate memory recall test was .

Interpret this result.

c. Here is summary information on scores on a controlled oral word-association test for the soccer and nonsoccer atheletes:

Analyze this data and draw appropriate conclusions.

d. Considering the number of prior nonsoccer concussions, the values of mean  sd for the three groups were

, and . Analyze this data and draw appropriate conclusions.