Legge, Klitz & Tjan (Psychological Review, 104, 524-553, 1997) have described an ideal-observer model for a simple reading situation. An ideal-observer model is an algorithm that yields optimal performance, given the constraints of the task. Mr. Chips is the name of a computer simulation that implements this ideal-observer model.
The purpose of the model is to examine how basic visual, motor and cognitive constraints influence reading behavior in people with normal and low vision. Legge, Klitz & Tjan (1997) show how this model provides novel accounts of characteristic patterns of normal eye movements in reading, including the presence of regressive saccades, word skipping, and a preferred viewing position in words. The paper also describes how the model provides insights into the reading difficulties encountered by people with visual-field loss resulting from eye disease.
We provide here a brief overview of the model followed by three examples of its behavior. Details can be found in Legge, Klitz & Tjan (1997).