From a Researcher's Notebook

This lesson was one of a series of lessons considering the nature of matter. In the immediately preceding lesson the pupils had investigated crystallisation. At the end of that lesson pupils had been encouraged by the teacher to try and grow salt (NaCl) crystals at home. The task of the lesson was identified - "today's work is on the board" (see above) but not explained by the teacher who then referred to the homework task in an attempt to develop a class discussion on particle behaviour associated with crystallisation - a discussion perceived by the teacher as orientating pupil thinking for the task to come. However, the pupil perceptions relating to their crystallisation experience did not seem to match those of the teacher.