Keystroke-level model

In human–computer interaction, the keystroke-level model (KLM) predicts how long it will take an expert user to accomplish a routine task without errors using an interactive computer system. It was proposed by Stuart K. Card, Thomas P. Moran and Allen Newell in 1980 in the Communications of the ACM and published in their book The Psychology of Human-Computer Interaction in 1983, which is considered as a classic in the HCI field. The foundations were laid in 1974, when Card and Moran joined the Palo Alto Research Center (PARC) and created a group named Applied Information-Processing Psychology Project (AIP) with Newell as a consultant aiming to create an applied psychology of human-computer interaction. The keystroke-level model is still relevant today, which is shown by the recent research about mobile phones and touchscreens (see Adaptions).Use Rule 0 to place candidate Ms, and then cycle through Rules 1 to 4 for each M to see whether it should be deleted.Place Ms in front of all Ps that select commands (not arguments).Guidelines:.08 (135 wpm: best typist).12 (90 wpm: good typist).20 (55 wpm: average skilled typist).28 (40 wpm: average non-secretary typist).50 (typing random letters).75 (typing complex codes)1.20 (worst typist and unfamiliar with the keyboard) In human–computer interaction, the keystroke-level model (KLM) predicts how long it will take an expert user to accomplish a routine task without errors using an interactive computer system. It was proposed by Stuart K. Card, Thomas P. Moran and Allen Newell in 1980 in the Communications of the ACM and published in their book The Psychology of Human-Computer Interaction in 1983, which is considered as a classic in the HCI field. The foundations were laid in 1974, when Card and Moran joined the Palo Alto Research Center (PARC) and created a group named Applied Information-Processing Psychology Project (AIP) with Newell as a consultant aiming to create an applied psychology of human-computer interaction. The keystroke-level model is still relevant today, which is shown by the recent research about mobile phones and touchscreens (see Adaptions). The keystroke-level model consists of six operators: the first four are physical motor operators followed by one mental operator and one system response operator: