We return to arguments made 10 years ago (Borgman, 1986a) that online catalogs are difficult to use because their design does not incorporate sufficient understanding of searching behavior. The earlier article examined studies of information retrieval system searching for their implications for online catalog design; this article examines the implications of card catalog design for online catalogs. With this analysis, we hope to contribute to a better understanding of user behavior and to lay to rest the card catalog design model for online catalogs. We discuss the problems with query matching systems, which were designed for skilled search intermediaries rather than end-users, and the knowledge and skills they require in the information-seeking process, illustrated with examples of searching card and online catalogs. Searching requires conceptual knowledge of the information retrieval process—translating an information need into a searchable query; semantic knowledge of how to implement a query in a given system—the how and when to use system features; and technical skills in executing the query—basic computing skills and the syntax of entering queries as specific search statements. In the short term, we can help make online catalogs easier to use through improved training and documentation that is based on information-seeking behavior, with the caveat that good training is not a substitute for good system design. Our long term goal should be to design intuitive systems that require a minimum of instruction. Given the complexity of the information retrieval problem and the limited capabilities of today's systems, we are far from achieving that goal. If libraries are to provide primary information services for the networked world, they need to put research results on the information-seeking process into practice in designing the next generation of online public access information retrieval systems. © 1996 John Wiley & Sons, Inc.