While external search effort has been studied for many years, its treatment has been limited to the amount of search effort and the motivating antecedent variables. Unlike previous research, this study is concerned with allocation of consumers' search efforts across many information sources and identifies what factors affect consumers' search behavior. In particular, this paper adds the Internet to the information sources used in the exiting studies as the new important information source so that five information sources -interpersonal sources, neutral sources, retailer, media, and the Internet-are used as typical information sources here. We emphasize the effect of different search type - ongoing and prepurchase search in consumers' search effort allocation and argue that certain information sources are used more heavily for ongoing search than for prepurchase search. In addition, we postulate a descriptive model of search effort allocation based on the economic theory of search and tests the hypothesized relationships using survey data obtained from a convenient sample of cellular phone purchasers. The results support the hypothesis that the search effort weights of the information sources are different with the search types. We also found that information quality is positively related to search benefit of the information source and that attitude is related to search benefit and cost. And information availability, ease of access, and knowledge and experience were found to be significant factors for some information sources.