B4.12
Keystroke-Level Model and Operator Constants
Cards in this group · 5
- B4.12.1Tasks are split into standard units such as keystroke, point, home, draw, mental preparation, and system response
- B4.12.2The placement of the mental preparation unit is governed by heuristic rules and is the main source of estimation error
- B4.12.3System response time counts toward the total only when it blocks the user
- B4.12.4Absolute constant values are questionable, but the differences between alternatives are relatively reliable
- B4.12.5Touch, voice, and gesture lack agreed-upon constants and must be measured before use