9. Gravetter/Wallnau/Forzano, - Chapter 14 - End-of-chapter question 14 Most sports injuries are immediate and obvious, such as a broken leg. However, some can be more subtle, such as the neurological damage that may occur when soccer players repeatedly head a soccer ball. To examine effects of repeated heading, McAllister et al. (2013) examined a group of football and ice hockey players and a group of athletes in noncontact sports before and shortly after the season. The dependent variable was performance on a conceptual thinking task. Following are hypothetical data from an independent-measures study similar to the one by McAllister et al. The researchers measured conceptual thinking for contact and noncontact athletes at the beginning of their first season and for separate groups of athletes at the end of their second season. Factor A: Sport Factor B: Time Factor B: Time Before the First Season After the Second Season n = 20 n = 20 Contact M - 9 M = 4 T - 180 T = 80 SS - 380 SS = 390 n = 20 n = 20 Noncontact M = 9 M = 8 T = 180 T = 160 SS = 350 SS = 400 EX= = 6,360 Use a two-factor ANOVA with a = .05 to evaluate the main effects and interaction. Source SS df MS F Between treatments A AXB within treatments TotalDo: Chapter 14 End-of-Chapter Problems Denominator Degrees of Freedom = 65 ANA 0.0 1.0 2.0 3.0 4.0 5.0 6.0 7.0 8.0 9.0 10.0 11.0 12.0 Use the Distributions tool to find the critical F values. (Use three decimal places.) F-criticalA F-critical F-critical A.B Is there a main effect for Factor A? Is there a main effect for Factor B? Is there an interaction? Calculate the effect size (n?) for the main effects and the interaction. (Use three decimal places.) NAB Briefly describe the outcome of the study. For the noncontact athletes, there is V difference between the beginning of the first season and the end of the second season, but the contact athletes show noticeably scores after the second season