Investigations in Mathematics Learning Official Journal of The Research Council on Mathematics Learning TABLE OF CONTENTS Volume 6, Number 1 - - Fall 2013 Preservice Teachers’ Understanding of Variable. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-17 Sue Brown, University of Houston – Clear Lake Judy Bergman, University of Houston – Clear Lake Abstract This study examines the research on middle school students’ understanding of variables and explores preservice elementary and middle school teachers’ knowledge of variables. According to research studies, middle school students have limited understanding of variables. Many studies have examined the performance of middle school students and offered suggestions on how to improve instruction in middle school. This study considers preservice elementary and middle school teachers’ knowledge of variables. A total of 73 preservice teachers, all candidates for Early Childhood – 6 certification, were given the same variable assessments completed by middle school students. Many of the misconceptions displayed by middle school students were also present in the results from preservice elementary and middle school teachers. This suggests that another means of improving middle school students’ performance in algebra is by strengthening the preservice elementary and middle school teachers’ understanding of variables. Middle School Children’s Mathematical Reasoning And Proving Schemes . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .18-40 Yating Liu, Old Dominion University Azita Manouchehri, The Ohio State University Abstract In this work we explored proof schemes used by 41 middle school students when confronted with four mathematical propositions that demanded verification of accuracy of statements. The students’ perception of mathematically complete vs. convincing arguments in different mathematics branches was also elicited. Lastly, we considered whether the students recognized and identified advantages associated with using justification models different from their own in order to offer a theoretical account for how individuals’ proof scheme choice might be impacted by such an exposure. Effects of Minute Contextual Experience on Realistic Assessment of Proportional Reasoning . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4168 Gabriel Matney, Bowling Green State University Jack L. Jackson II, University of Arkansas Jonathan Bostic, Bowling Green State University Investigations in Mathematics Learning Official Journal of The Research Council on Mathematics Learning Abstract This mixed methods study describes the effects of a minute contextual experience on students’ ability to solve a realistic assessment problem involving scale drawings and proportional reasoning. Minute contextual experience (MCE) is defined to be a brief encounter with a context in which aspects of the context are explored openly. The study looked closely at what happened during an instructional unit examining proportional reasoning. Students completed a pretest and posttest involving items characterizing a novel context, and data were analyzed to determine the effects of the MCE. Students were interviewed to gather their perspectives on the problem and their own solutions. Pretest results indicated that instruction in which student demonstrated growth in understanding had little effect on students’ ability to solve a novel problem in which they had difficulty associating their everyday mundane knowledge with the realistic context. The students demonstrated a significant increase in ability to solve the novel problem after a MCE. Furthermore, student explicated that the MCE aided their ability to visualize the context, and this helped them apply instructional learning to solve the problem. A discussion of the complexities involving the assumptions of students’ familiarity with contexts and their abilities to draw upon their mundane everyday experiences to solve proportional reasoning problems is shared.