Two elementary school teachers were members of a large sample participating in a study of changing teacher practices through intervention with staff developers. In October, one teacher was transferred to a similar school in another part of the district. The other teacher accepted an assignment in another school at the end of the first semester. These schools had staff developers not participating in the larger study. Both teachers continued working with the Research in Teacher Education staff through an intervention with staff developers. The researchers explored teachers' stages of concern and teacher development; organizational change; teacher effectiveness; and contextual influence on teaching. Discussion of the two cases focuses on four central questions: (1) What were the teachers' personal and professional characteristics, and did these relate to perceptions of the initial class assignments? (2) Did the teachers change their classroom practice as a function of the multiple layers of change they experienced? (3) Who initiated the changes in classroom assignments, and how did the teachers feel about the changes? and (4) What contextual changes occurred as a result of the new assignments, and how (if at all) did these relate to the teachers' perceptions and practices? (JD)