Simulating Errors in Touchscreen Typing

TL;DR

This paper extends computational models of touchscreen typing errors to include cognitive mechanisms like lapses and mistakes, using a supervisory control framework to simulate human-like error patterns and inform better text entry system design.

Contribution

It introduces a novel cognitive model, Typoist, that simulates various error types in touchscreen typing and predicts performance for improved system design.

Findings

Model accurately simulates human error patterns

Predicts performance metrics for different user parameters

Provides insights for designing better text entry interfaces

Abstract

Empirical evidence shows that typing on touchscreen devices is prone to errors and that correcting them poses a major detriment to users' performance. Design of text entry systems that better serve users, across their broad capability range, necessitates understanding the cognitive mechanisms that underpin these errors. However, prior models of typing cover only motor slips. The paper reports on extending the scope of computational modeling of typing to cover the cognitive mechanisms behind the three main types of error: slips (inaccurate execution), lapses (forgetting), and mistakes (incorrect knowledge). Given a phrase, a keyboard, and user parameters, Typoist simulates eye and finger movements while making human-like insertion, omission, substitution, and transposition errors. Its main technical contribution is the formulation of a supervisory control problem wherein the controller allocates cognitive resources to detect and fix errors generated by the various mechanisms. The model generates predictions of typing performance that can inform design, for better text entry systems.