This study, part of a larger study on special education teacher expertise, compared the instructional decision making of expert and novice special education teachers in familiar instructional settings to determine differences in the allocation of attention to different instructional themes. Participants were 19 expert special education teachers and 19 student teachers majoring in special education. Two one-hour videotapes were made of each teacher in the classroom, observations were made in conjunction with each videotaping session, and stimulated recall procedures were used to obtain teachers' reflections about the process videotaped. Teacher reflections were coded into 11 categories which fell under three conceptual themes: (1) teacher on-line assessment of students, (2) teachers' tacit knowledge of students, and (3) classroom strategies. Expert teachers reflected significantly more often than did novices concerning student "state of mind," students' prior knowledge, and students' typical behavior patterns. Expert teachers strategically and reflectively applied a variety of instructional interventions that were based on both their background knowledge and the information they gathered during instruction. Experts expressed significantly more comments about instructional strategies and collaboration/consultation than did novices, but the two groups did not differ in regard to the behavioral, monitoring, or management strategies mentioned. (Contains 30 references.) (DB)