A Componential Model of Human Interaction with Graphs. III. Spatial Orientation

The Mixed Arithmetic-Perceptual (MA-P) model of graph comprehension proposes that graph users apply combinations of component processes — including Searching for indicators, Encoding the value of indicators, performing Arithmetic Operations on the values, making Spatial Comparisons among the indicators, and Responding — when they answer questions from a graph. The model further suggests that the combination and order of the components that the user applies depends on a user's task and the type of graph. The present research investigated the use of another component process — mental rotation — in interacting with star graphs. Subjects used two star graphs to answer comparison and difference questions in which the differences in orientation of the indicators in question varied from 0 to 288°. The results showed a nonmonotonic change in response time with the difference in orientation. The discussion addresses the effects of mental rotation in reading displays and the role that rotation may play in the hierarchy of graph effectiveness proposed by Cleveland and McGill.