Copyright Malvin Porter, Jr. 2010 - acumen - The University of ...

Table 28
CBVS Test and Confidence Interval for the Proportion of Bystander and the Proportion of
Victims Among Children who Selected Prosocial Action Choices
Sample ƒ n Sample p
Bystander 230 316 0.727848
Victim 258 316 0.816456
Test of p = 0 vs. p ≠ 0
Difference = p (Bystander) – p (Victim)
Estimate for difference: -0.0886076
95% CI (-0.153644, -0.0235711)
Test for difference = 0 (vs. ≠ 0): Z = -2.67 P-Value = 0.008
Fisher's exact test: P-Value = 0.010
N = 632 responses
A test for the Difference in Proportions tested the following null hypothesis: There is no
difference between children’s CBVS Aggressive Action Choices for stories that involved
bystander story characters and the proportion of children CBVS Aggressive Action Choices for
stories that involve victim story characters
Of the 316 responses to the Bystander Story Character scenarios, 86 were Aggressive
Action Choices. Of the 316 responses to in the Victim Story Character scenarios, 58 were
Aggressive Action Choices. The estimate of the difference in the proportion of children’s
Aggressive Action Choice responses when the Story Character was a bystander and the
proportion of children’s Aggressive Action Choice responses when the Story Character was a
Victim was 0.0886076. The hypothesized difference in proportions of zero does not lay within
the 95% CI (0.0235711, 0.153644) for the difference in proportions of children’s Aggressive
Action Choice responses when the story character was the bystander and when the story
character was the victim. Therefore, zero is not a plausible value for the difference in proportions
of children’s Aggressive Action Choice responses between victim and bystander story character
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