Prompting of reading errors is a common pattern of teaching behavior occurring in reading groups. Teachers' tactics in responding to pupil errors during oral reading in public school classrooms were analyzed with the assistance of the technology of the Computer Assisted Teacher Training System (CATTS) to formulate hypotheses about teacher decision making in interactive teaching. An observation schedule constructed to code teacher and pupil moves in oral reading was used to gather data from 34 teachers as they taught oral reading lessons. The observed prompting tactics, variations in success rate in prompting, and data from a stimulated recall interview of teachers suggested models of teacher information processing and decision making. (Author)