Guilt in decision making. The effect of guilt emotion on how a decision-maker focuses on the problem was investigated in the January 2007 issue of the Journal of Behavioral Decision Making. A sample of 77 volunteer students participated in one portion of the experiment, where each was randomly assigned to one of three emotional states (guilt, anger, or neutral) through a reading/writing task.
(Note: Twenty-six students were assigned to the ‘‘guilt'' state, 26 to the ‘‘anger'' state, and 25 to the ‘‘neutral'' state.) Immediately after the task, the students were presented with a decision problem where the stated option has predominantly negative features (e.g., spending money on repairing a very old car). Prior to making the decision, the researchers asked each subject to list possible, more attractive, alternatives. The researchers then compared the mean number of alternatives listed across the three emotional states with an analysis of variance for a completely randomized design. A partial ANOVA summary table is shown below.
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SOURCE
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df
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F-VALUE
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p-VALUE
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Emotional State
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2
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22.68
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0.001
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Error
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74
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Total
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76
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(a) What conclusion can you draw from the ANOVA results?
(b) Explain why it is inappropriate to apply Tukey's multiple comparisons procedure to compare the treatment means.
(c) The Bonferroni multiple comparisons of means procedure was applied to the data using an experimentwise error rate of .05. Explain what the value, .05, represents.
(d) The multiple comparisons yielded the results shown in the next column. What conclusion can you draw?
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Sample mean:
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1.90‾
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2.17‾
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4.75
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Emotional state:
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Angry
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Neutral
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Guilt
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