Human Factors Criteria for the Design and Acquisition of ... - FAA

Keyboards June 2004Primary keyingareaPronationThe area that is easily reachable from the home positionwith the fingers resting on the home row of keys.Rotation of the hand and forearm so that the palm facesdownward.QWERTYkeyboardSnap actionSplit keyboardStrike surfaceSupinationToggle keysA keyboard layout based starting with the lettersQWERTY in the upper left part of the keyboard alsoknown as the Sholes keyboard.A spring mechanism that produces a rapid buildup ofresistance on the downstroke of a key with a sharp drop offin mid travel at the point of switch closure.A keyboard that has the primary keying area split into twoportions (generally between the tgb and yhn keys) in aneffort to promote a more neutral, more ergonomic wristposition.The top surface of the key. The primary area where thefinger touches the key.Rotation of the forearm and hand so that the palm faces up.Keys that change their state when pressed once and changeback to the original state when pressed a second time.Also known as dual state keys. An example is the CapsLock key.9-45