Student Difficulties with Graphs in Different Contexts

Abstract

This study investigates university students’ strategies and difficulties with graph interpretation in three different domains: mathematics, physics (kinematics), and contexts other than physics. Eight sets of parallel mathematics, physics, and other context questions were developed and administered to 385 first year students at Faculty of Science, University of Zagreb. In addition, the questions were administered to 417 first year students at the University of Vienna. Besides giving answers to the questions in the test, students were also required to provide explanations and procedures that accompanied their answers so that additional insight in the strategies that were used in different domains could be obtained. Rasch analysis of data was conducted and linear measures for item difficulties were produced. The analysis of item difficulties obtained through Rasch modeling pointed to higher difficulty of items which involved context (either physics or other context) compared to direct mathematical problems on graph. In addition, student explanations were analyzed and categorized. Student strategies of graph interpretation were found to be largely domain specific. In physics, the dominant strategy seems to be the use of formulas, especially among students at the University of Zagreb. This strategy seems to block the use of other, more productive strategies, which students possess and use in other domains. Students are generally better at interpreting graph slope than area under the graph which is difficult for students and needs more attention in physics and mathematics teaching.