A researcher is attempting to determine the effects of practice and gender on a timed task. Participants in an experiment are given a computerized search task. They search a computer screen of various characters and attempt to find a particular character on trial. When they find the designated character, they press a button to stop a timer. Their reaction time in seconds) on each trial is recorded. Subjects practice for 2, 4, or 6 hours and are either female or male. The reaction time data for the 30 subjects appear here.
Women Men
2 Hours 12 11
13 12
12 13
11 12
11 11
4 Hours 10 8
10 8
10 10
8 10
7 9
6 Hours 7 5
5 6
7 8
6 6
7 8
Source df SS MS F
Gender 0.027
Practice 140.60
Gender x Practice 0.073
Error 28.00
Total 168.70
a) Complete the ANOVA summary table.
b) Are the values of F obt significant at α = .05?
c) What conclusions can be drawn from the F-ratios?
d) What is the effect size, and what does this mean?
e) Graph the means.