The purpose of this study is to develop a new approach and assess the application for the science and technology student-teachers to gain varied laboratory methods in science and technology teaching. It is also aimed to describe the computer-assisted POE application in the subject of "Photosynthesis-Light" developed in the context of this approach choosing the most appropriate design software called "Flash Player 10.1". The study was applied during the fall semester in the 2009-2010 and 2010-2011 academic year with 188 science and technology student-teachers who attended the course of Science and Technology Laboratuvar Applications-I at the Karadeniz Technical University Fatih Faculty of Education based on action research methodology. The survey's data was analyzed with SPSS 16.00 using descriptive statistics based on mean and standard deviation. The interviewing data was analyzed according to common views. In this study, the implementation process of a developed approach was explained and an example of the computer-assisted POE application in the subject of "Photosynthesis-Light" was described. It was concluded that the developed approach introduces the science and technology student-teachers to an efficient and reflective process to gain varied methods in laboratory applications. (Contains 2 tables and 10 figures.)