Online information retrieval is pervasive and its development in libraries is accelerating. Within the near future, most college and research libraries will provide direct access to their patrons to vast information resources via CD-ROMs, locally mounted databases, and gateways. The computer terminal and the "frame" of information it provides will take its place as a perceptual icon the user identifies with information and its acquisition. Although online retrieval is very powerful, it is also quite abstract, and hence will present perceptual problems to the user. A key to resolving the perceptual problem will be understanding the nature of algorithmic problem solving. It is through the algorithm that natural logic to formal logic transformation occurs during interactive searching. Since the algorithm is of such importance, this paper examines both its intrinsic value to online retrieval and its inherent problematic nature. Included is the notion of the algorithm as a "natural barrier" to the heuristic-oriented searcher. (19 references) (Author)