This thesis presents a case study of the thinking and practice of an experienced primary teacher as he planned and taught a term's science topic on toys with his class of 9-10 year olds. The teacher planned the topic as a series of activities intended to promote investigation and problem-solving by his pupils. Most of the time pupils worked
in small groups, testing and making vehicles or models. Information about the teacher's theories and his plans for teaching the topic was collected through interviews, conversations and written notes over the school year. In the third term, when the topic was taught, his
actions and thoughts in the lessons were traced through classroom observation and audiorecording.
Analysis of the teacher's theories identified his beliefs and his repertoire of knowledge on which he drew in planning; his specific subject knowledge in science was related to his general theories of teaching and learning.
His planning was seen to be a layered process in which he formed images of the flow of activity in each layer: the year, term, activity and lesson. The teacher's thinking during lessons, referred to as thinking-in-action, was closely related to the classroom action but involved more than thoughts about immediate interactions and decisions.
The analysis of dilemmas identified by the teacher provided insights into the nature of his thinking-in-action and its influence on his theories.
The relationship of thinking and practice in this case of teaching was compared to Schon's (1983.1987) account of the reflective practice of professionals, particularly to his concept of reflection-in-action. A model was developed within which a teacher's theories, planning and thinking-in-action can be related to one another and to action in a particular situation. Implications for research into teachers' thinking, for primary science and technology, and for the professional development of teachers are discussed.