Using the Keystroke-Level Model to Estimate Execution Times
David E. Kieras · 2003
The Keystroke-Level Model (KLM), proposed by Card, Moran, & Newell (1983), predicts task execution time from a specified design and specific task scenario. Basically, you list the sequence of keystroke-level actions the user must perform to accomplish a task, and then add up the times required by the actions. It is not necessary to have an implemented or mocked-up design; the KLM requires only that the user interface be specified in enough detail to dictate the sequence of actions required to perform the tasks of interest.