The purpose of this study was to determine the effect of expertise on prechoice decision processes and final outcomes. By decomposing verbal protocols collected from 90 individuals who made one complex, mortgage loan decision, we could compare the frequency and type of elementary information processes evoked. We found that experts, relative to less knowledgeable decision makers, made a greater number of problem framing statements; made more references to why an option was being retained for further consideration; and used more compensatory decision rules. In addition, we found that misunderstanding externally provided information mediates the expertise‐choice relationship. Novices were significantly more likely to misunderstand information than were more knowledgeable decision makers. As a result, there was greater variance in novices’ final choices than was the case with experts’. The deleterious effect of mis‐understandings is disconcerting because consumers frequently miscomprehend print communications.