A cost analysis was made of on-line bibliographic searching in four public libraries in the San Francisco Bay Area using the Lockheed DIALOG system. The study involved monitoring the time that 35 individuals in the libraries spent processing some 411 search requests. The study identified a set of seven tasks that are performed for each request and determined the average time and cost for each of the tasks. The average total search cost was $28.41, exclusive of telephone line charges. This figure does include the data base connect charges of $17.29. The average time required to process a request was 7.8 calendar days. A wide variation in the cost and time figures was found among the four libraries and among individual searchers. (Author/JY)