GOMS

A family of human-computer interaction models used to predict how long it will take a user to complete a task with a given interface. GOMS stands for Goals, Operators, Methods, and Selection rules — the four components used to describe user behavior. The simplest variant, the Keystroke-Level Model (KLM), estimates task time by summing the durations of individual actions like keystrokes, mouse clicks, and mental preparation. More complex variants like CPM-GOMS model parallel cognitive and motor activities. While widely used in interface design, GOMS models were developed for able-bodied expert users and do not account for the different interaction patterns, motor timing, and cognitive strategies of users with disabilities, limiting their applicability to accessible interface evaluation without modification.