Performance assessment is an important task in all levels of education, both as input for identifying remedial needs of individual students and for improving general quality of education. Although explicit assessment measures can be obtained through objective standardized testing, it is much more difficult to capture fuzzier, or tacit, performance assessment measures. The problem of tacit knowledge capture is a central theme in the field of knowledge management, and assessment management can be thought of as a form of knowledge management. Therefore, tacit assessment management can be facilitated through technologies commonly used in knowledge management systems such as databases, Internet architectures, artificial intelligence, and decision support techniques. This paper describes tacit performance assessment in the context of knowledge management and presents a prototype decision support system for managing tacit assessment knowledge using knowledge management techniques.