Individual differences in teacher development: An exploration of the applicability of a stage model to assess individual teachers

Researchers have recently become interested in exploring cumulative order in teachers' use of teaching practices, which they argue may reflect stages in teacher development. However, to validly apply stage models to individuals, it is necessary to determine whether all teachers fit the stage order. This study explores whether and in how many lessons observed teaching practices do not fit the stage order and whether misfit is typical to certain teachers, which would indicate individual differences. The sample consists of 198 classroom observations of 69 teachers (two to four lessons for each teacher). Using person-fit methods, the study shows that 17% of the 198 observed lessons substantially misfit the stage order but that misfit is not characteristic to specific teachers, suggesting that it is incidental. Removing the occasional misfitting lessons allows the stage model to provide an appropriate description of teaching skill.