11. Gravetter/Wallnau/Forzano, Essentials - Chapter 13 - End-of-chapter question 11
Most sports injuries are immediate and obvious, such as a broken leg. However, some can be more subtle, such
occur when soccer players repeatedly head a soccer ball. To examine effects of repeated heading, McAllister et
and ice hockey players and a group of athletes in noncontact sports before and shortly after the season. The de
conceptual thinking task. Following are hypothetical data from an independent-measures study similar to the o
measured conceptual thinking for contact and noncontact athletes at the beginning of their first season and for
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
Noncontact
M = 9
T = 180
SS = 380
n = 20
M = 9
T = 180
M = 4
T = 80
SS = 390
n = 20
M = 8
T = 160
SS = 350
SS = 400
ΣΧ² = 6,360
Use a two-factor ANOVA with a = .05 to evaluate the main effects and interaction.
Source
Between treatments
A
SS
df
MS
F