This chapter describes teachers' perceptions, of the dilemmas created by their efforts to implement 'Patterns', the schools Council 'Integrated Science Project' (SCISP) in order to illuminate the nature of dilemmas endemic in the teachers' world and magnified by proposals to change radically habitual practice. It focuses on the dilemma of influence as it emerges from the use of an inquiry approach to science teaching. The SCISP designers urged that a partnership between pupil and teacher be fostered. Teachers reported a dilemma in controlling inquiry lessons. Ironically, some of the teachers thought that the SCISP students were often too critical. The analysis of the bipolar factors suggested that teachers appraised different teaching events in terms of the extent of their involvement in the event. The discussion of influence is organised into three parts: forms of high influence teaching: teacher as 'prime mover' and 'navigator'; and low influence teaching; teacher as 'referee'.