1. Analysis of Variance
One-Way ANOVA

2. Researchers were interested in the relationship between the presence of other people and helping behaviors. In an extension of the Darleys (1968) classic study, the experimenter (a female graduate student) asked participants to wait in a room with either 0, 2, or 4 confederates.
The experimenter announces that the study will begin shortly and walks into an adjacent room. In a few moments the person(s) (0, 2, or 4) in the waiting room hear her fall and complain of ankle pain. The dependent measure is the number of seconds it takes the participant to help the experimenter.
Darley, J. M.; Latan, B. (1968). Bystander intervention in emergencies: Diffusion of responsibility. Journal of Personality and Social Psychology 8: 377383.
3. http://faculty.vassar.edu/lowry/VassarStats.html
Number of Confederates
0 2 4
number of seconds
4. Number of Confederates
0 24
95% CI:1.96 (SE)Mean
1.96(2.0881)Mean
=4.699 5= 2.0881
5. 3
6. 35
30
Time (seconds)
95% CIs
1.96 (2.0881)Mean
No difference in response time between 0 and 2
because CIs overlap.
25
0 2 4
NUMBER OF CONFEDERATES PRESENT