This paper reports findings about a curriculum innovation conducted at The University of Hong Kong. A CD-ROM consisting of videos of two lessons by different teachers demonstrating exemplary science teaching was used to elicit conceptions of good science teaching of student-teachers enrolled for the 1-year Postgraduate Diploma in Education at several stages during the programme. It was found that the videos elicited student?teachers' conceptions and had impact on those conceptions prior to the commencement of formal instruction. It has extended student-teachers' awareness of alternative teaching methods and approaches not experienced in their own schooling, broadened their awareness of different classroom situations, provided proof of existence of good practices, and prompted them to reflect on their current preconceptions of good science teaching. In several ways, the videos acted as a catalyst in socializing the transition of student-teachers from the role of student to the role of teacher.