Revision with unchanged content. Current educational operation for informal science institutions tends to be based on the staff’s experience and intuition rather than on educational theories or research findings. This status study sought research evidence to develop an Educational Scheme for informal science institutions. Evidence for this scheme came from surveys to determine specific circumstances of educational operations, visitor behaviors and ethnographical research . The Discrepancy Model seeking gaps between the actual and desired states guided this investigation of how the staff view the nature and status of educational operations. Institutional data were collected as a form of a survey asking about actual and desired states in terms of goals and roles of staff, contents of exhibits and programs, assessment, and professional development each for administrators and practitioners. Another investigation sought visitors’ views of the effectiveness of the main idea for exhibit understanding, effective labels, expectations toward on-site lessons, and possibilities for a long-term assessment. A needed direction was proposed to develop the Scheme.