The academic debate concerning public opinion about war focuses upon two explanations: cost/benefits and partisan cues. Both sides of this debate use laboratory experiments to estimate the influence of events and cues, but Gelpi is notable for using a well-designed experiment to compare the theories simultaneously. He argues that his results support the cost/benefits explanation as "surprising events" that counter individuals’ prior attitudes have significantly more effect than "surprising opinions" upon people’s attitudes toward the Iraq War. His analysis, however, considers only the direction, but not the strength, of people’s attitudes toward the war. Additionally, the measure of source credibility for determining the influence of cues is not optimal. When the analysis accounts for attitude strength and uses a better measure of source credibility, the results show little support for the effect of surprising events and markedly greater support for the influence of partisan cues.