Longitudinal differences in the expression of expertise : a case study of teacher thought and action

This case study described the professional practical knowledge, a combination of thoughts and actions, of one expert teacher of children with severe disabilities over two time frames: during the first year of a change in teaching assignment (a novice-like year) and then again in the third year of implementation in the same setting (an expert year). Differences in professional practical knowledge between these two time frames were compared through the filters of the Dreyfus model for the development of expertise and literature describing novice-expert differences in teacher thinking. Participant observations, interviews, artifact collections, and a self-reporting system called "verbal journals" were used to collect and uncover thoughts and actions embedded in practice. The data were analyzed using qualitative methods. The following results were described:

1. The teacher's interpretations changed from a literal following of recommended practices to a contextual and holistic adaptation that required a depth of understanding of the meaning behind the practice.

2. The teacher's routines changed from an emphasis on development that remained disconnected and choppy to their use as systems for obtaining broader goals.

3. Teaching became more sophisticated, combining systems to extend lessons to a more sophisticated level.

4. The teacher's expression changed from highly descriptive explanations during the time she was attempting to implement the program to tacit and embedded in practice after routines and organizational systems were established.

5. Descriptions of emotion changed from discomfort during the period of initial change to investment and appreciation during the third year of implementation. The findings support the notions that expertise develops in stages and that a change in assignment can produce a disruption to expertise. The teacher showed considerable variation in professional practical knowledge among tasks, however, suggesting that expertise was a specific and dynamic, rather than a generalized, concept. Professional practical knowledge was revealed through episodic descriptions that required entry into the teacher's world to understand. Finally, the experience of change in assignment was emotionally laden, accompanied by reports of distress.

Implications are offered for teacher training, utilization of professional staff, and teacher evaluation systems.