Computer simulations in physics teaching and learning: a case study on students' understanding of trajectory motion Athanassios Jimoyiannis a, *, Vassilis Komis b a 2nd Technical School of Ioannina, Kaliafa 2, Ioannina 45332, Greece b Department of Early Childhood Education, University of Patras, Rio 26500, Greece Received 24 April 2000; accepted 15 November 2000 Abstract A major research domain in physics education is focused on the study of the eects of various types of teaching interventions aimed to help students' alternative conceptions transformation. Computer simulations are applications of special interest in physics teaching because they can support powerful modeling envir- onments involving physics concepts and processes. In this study two groups (control and experimental) of 15±16 years old students were studied to determine the role of computer simulations in the development of functional understanding of the concepts of velocity and acceleration in projectile motions. Both groups received traditional classroom instruction on these topics; the experimental group used computer simula- tions also. The results presented here show that students working with simulations exhibited signi®cantly higher scores in the research tasks. Our ®ndings strongly support that computer simulations may be used as an alternative instructional tool, in order to help students confront their cognitive constraints and develop functional understanding of physics. # 2001 Elsevier Science Ltd. All rights reserved. Keywords: Simulations; Interactive learning environments 1. Introduction Learning physics is often considered by teachers and students to be a dicult pursuit. Over the last two decades a great deal of educational research has been directed towards the exploration of students' ideas and diculties on physical concepts and processes (Driver, Guesne & Tiberghien, 1985; Duit, Goldberg & Nidderer, 1991). Research on physics and science education has often focused on the study of alternative conceptions and mental representations that students employ 0360-1315/01/$ - see front matter # 2001 Elsevier Science Ltd. All rights reserved. PII: S0360-1315(00)00059-2 Computers & Education 36 (2001) 183±204 www.elsevier.com/locate/compedu * Corresponding author. E-mail address: ajimoyia@cc.uoi.gr (A. Jimoyiannis).