According to purchasing decision models, consumers make purchases through a series of problem-solving processes that involve collecting necessary information and evaluating alternatives after recognizing a need to purchase a particular product (problem recognition). However, numerous research studies reveal that consumers obtain information and evaluate brands even before problem recognition occurs, thereby simplifying the situation and making efforts to reduce the set of choice alternatives to facilitate decision-making, and that these efforts continue even after a purchase has been made. Therefore, based on these findings, this study constructed a multi-stage brand evaluation model and, as a means of verifying whether consumers actually engage in multi-stage evaluation, investigated whether the size of the consideration set changes across theoretical stages, and whether there are differences in the amount of information search and the relative usage weight of information sources. If clear differences exist at each stage, this would signify that multi-stage brand evaluation is indeed taking place. The analysis results showed that information search and evaluation of specific products occur even before there is a purchase plan, and the same holds true after purchase. The size of the consideration set was largest when no purchase plan existed, decreased as the purchase approached, and showed a tendency to increase again as time passed after the purchase. The amount of information search was relatively low before a purchase plan existed, became most active after the purchase plan was finalized, and tended to decrease again after the purchase was made. Advertising information had the highest relative usage weight when no purchase plan existed; its relative dependence decreased after a purchase plan was formed, and then rose again after purchase. Personal information sources were highly utilized across all stages, and their usage became even higher than advertising information after purchase. Neutral information sources were used at a consistent level across all processes, though not at high levels, while retail store information sources had generally low utilization but showed a relatively higher dependence during the purchase planning stage. Thus, the multi-stage brand evaluation model was empirically verified, albeit indirectly.