Simulating a Skilled Typist: A Study of Skilled Cognitive‐Motor Performance

TLDR

The study reviews skilled typing phenomena and proposes a model for hand and finger control during typing. The model employs an Activation‑Trigger‑Schema system with hierarchical schemata that select letters and drive hand/finger movements via a cooperative relaxation algorithm, using activation/inhibition patterns to time keystrokes and a weak binding for doubling errors, and is implemented as a working computer simulation. The simulation reproduces key typing phenomena such as interkeystroke intervals, transposition errors, and doubling errors, showing that the model is a useful first approximation despite its limitations.

Abstract

We review the major phenomena of skilled typing and propose a model for the control of the hands and fingers during typing. The model is based upon an Activation‐Trigger‐Schema system in which a hierarchical structure of schemata directs the selection of the letters to be typed and, then, controls the hand and finger movements by a cooperative, relaxation algorithm. The interactions of the patterns of activation and inhibition among the schemata determine the temporal ordering for launching the keystrokes. To account for the phenomena of doubling errors, the model has only “type” schemata—no “token” schemata—with only a weak binding between the special schema that signals a doubling, and its argument. The model exists as a working computer simulation and produces an output display of the hands and fingers moving over the keyboard. It reproduces some of the major phenomena of typing, including the interkeystroke interval times, the pattern of transposition errors found in skilled typists, and doubling errors. Although the model is clearly inadequate or wrong in some of its features and assumptions, it serves as a useful first approximation for the understanding of skilled typing.