Teachers' Knowledge of Science Concepts

We developed a three level scoring scheme to score the depth of teachers’ responses. Teachers’ responses were given a score of 0 if teachers provided incorrect or equivocal responses; a score of 1 if teachers provided correct, seemingly intuitive responses, but without an accurate, complete scientific explanation; and finally, a score of 2 if teachers provided correct responses along with a scientific explanation drawn from the core ideas in the curriculum.

Using this scoring scheme, we calculated the total pre– and post–interview score for each teacher; the total number of pre- and post-interview level 2 responses for each teacher; the pre– and post–interview scores for each teacher in each of the six content areas; and the number of pre– and post–interview level 2 responses for each teacher in each of the six content areas.

Our findings suggest that after implementing the curriculum as part of the Talk Science program, teachers articulated their understandings about the nature of matter by drawing increasingly on the concepts and principles from the curriculum. They showed greater facility in explaining processes such as evaporation, condensation, and dissolving of salt in water with the help of the particle model from the curriculum, and understood that matter is made of particles that have weight and take up space. On the post–interview, all teachers obtained a higher total score (see Figure 1), and provided more responses that were assigned a score of 2 (see Figure 2; indicating their ability to provide elaborate scientific explanations on the basis of the core science concepts and ideas from the curriculum).

In the following section, we provide details on the changes in teachers’ understandings within each of the six content areas that were examined through the interview.