Interpreting Functions of One-Dimensional Kinematics
thesisposted on 20.06.2014, 00:00 by Reality S. Canty
The present work examined several factors related to interpreting graphical representations of motion concepts. Since the seminal work of Larkin and Simon (1987), cognitive research has investigated informational equivalence and computational efficiency by contrasting performance across different representations systems such as line versus bar graph (Ali & Peebles, 2012; Shah & Freedman, 2009; Zacks & Tversky, 1999), table versus graph (Speier, 2006; Vessey, 1991) or table versus map (Smelcer & Carmel, 1997). Physics education research has focused on difficulties related to interpreting motion concepts in graphs, accounting for them in terms of misconceptions. Kinematics, the branch of physics concerned with the motion of objects, makes an interesting study of informational equivalence and computational efficiency because its three primary representations – position-time, velocity-time, and acceleration-time graphs – can reflect the same information in the same representational system which provides a different type of contrast than has usually been used in this area of cognitive research. In the present work, four experiments were used to test several hypotheses concerned with whether information about the motion of objects can be directly read-off the graph or whether it needed additional processing beyond what was directly visible; Palmer (1987) referred to this as the derivational structure of representations. The main findings across the four experiments were that (a) graph type was not a reliable factor of graph interpretation difficulty, (b) derivational structure was useful for analyzing tasks but there was no evidence supporting it as a process account, (c) graph-based judgment is susceptible to visual features in the graph that trigger powerful spatial-conceptual correspondences particularly height (e.g., higher means more, lower means less), direction of slope (e.g., zero, positive, negative), and curvature (e.g., increasing rate of change, decreasing rate of change), (d) subjects primarily based their judgments on information from these features even when interpretation demanded more elaborate inferences with respect to the actual properties of motion depicted, and (e) domain knowledge was not enough to override the spatial-conceptual correspondences that biased judgment.