A model of eye movements and visual working memory during problem solving in geometry

The Oculomotor Geometry Reasoning Engine (OGRE) was proposed to model eye m ovements and visual working memory during problem solving in geometry. OGRE postulates that geometrical elements from diagrams are added to visual wor king memory when they are scanned. Newly-added elements overwrite elements already in memory. The model was applied to eye-movement patterns of three subjects: two geometry experts and one non-expert. Their eye movements and verbal protocols were recorded as they solved geometry problems posed with diagrams. Subjects used highly redundant eye-movement patterns with multipl e rescans of the same geometrical elements. OGRE's model of visual memory p rovided a good fit for the distribution of times between rescans. The model was used to estimate the size of visual working memory used in geometry. T he estimates varied as a function of both problems and subjects, with means and standard deviations for each subject being: 5.3 +/- 1.4, 4.0 +/- 0.9 a nd 4.7 +/- 1.6. (C) 2001 Published by Elsevier Science Ltd.