This article uses an information processing approach to analyze the erasures of end-users from National Taiwan University in searching online bibliographic databases. The end-users are 45 students and 2 faculty. After instruction, subjects search through the semester, doing 60 searches. Through analyzing the timed keystroke data, this study identified 112 reasons for erasures. In this study, erasures occurred most frequently in connection with functions, moves, and elements of "create and develop sets" and "display and print records". In addition, most erasures are recognized mistakes and subjects do chunk little information online. The results also indicate end-users conduct less erasures and spent less time in finishing an erasures as they gain more experience and practice.