This study investigated whether the criterion-related validity coefficient of the Instructional Strategy Usage (ISU) instrument was statistically significant, and investigated factors related to general education teachers' use of instructional strategies that facilitate inclusion of students with moderate and severe impairments in general education classes. Teachers (n=110) from 47 Michigan school districts completed the ISU, and 15 teachers were observed in their classrooms. Research findings indicated that: (1) the criterion-related validity coefficient of the ISU was statistically significant; (2) years of teaching experience of general education teachers was negatively related to their use of instructional strategies that facilitate inclusion of students with moderate and severe impairments in general education classes; (3) general education teachers' training in the field of special education was unrelated to their use of instructional strategies that facilitate inclusion; (4) general education teachers' collaboration with special education teachers, including a building principals's support, was positively related to their use of instructional strategies that facilitate inclusion; and (5) self-perceived efficacy of general education teachers was unrelated to their use of instructional strategies that facilitate inclusion. (Contains 29 references.) (Author/JDD)