Cost-Justifying Usability, 2nd Edition

Keystroke Level Modeling as a

Cost Justification Tool

Deborah J. Mayhew Deborah J. Mayhew & Associates

16.1 INTRODUCTION

Keystroke level modeling (KLM) is one of a variety of cognitive modeling tech-

niques that have been reported in the literature over the last two decades. It is

the original modeling technique described by Card, Moran, and Newell in their

classic book The Psychology of Human-Computer Interaction (1983). It is the simplest

and most basic of a family of modeling techniques (e.g., GOMS, which stands

for goals, operations, methods, and selection rules) that have evolved from it

over the past two decades (John, 1990, 1995; John and Kieras, ...