Teacher practice course plays a vital role in preservice teacher education. As a part of this course, preservice teachers are expected to observe classroom dynamics and to practice the theoretical framework and skills they were taught during the three years of their education. The use of videos can be a useful instructional tool to present different cases to preservice science and technology teachers. However, one aspect of the effectiveness of this approach relies on preservice teacher's ability to recognize strength and weaknesses of teaching practices. Therefore, this study focuses on preservice teachers' ability to notice strength and weaknesses of teaching. (C) 2010 Elsevier Ltd. All rights reserved.