When choosing her examples in lesson 2 she was far more focused, relying on earlier
experiences. For example, just to show the relation between force and pressure she
explained the definition of force she uses a football and contrasted three different
ways of how force could act on the ball. She put the ball on a table to discuss the
forces, she kicked the ball and finally she pressed her hand against the ball, both
with one finger and then with her whole hand. By doing this, Amy actively integrated
2850 P. Nilsson and A. Vikström
her knowledge of subject matter; science curriculum (i.e. the difference and relations
between force and pressure) and students’ misconceptions associated with these ideas,
and then applied the resulting PCK to the students through instructional strategies
such as questioning and discussion.