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

Keyboards June 20049.5.2.2 Grouping by function. Keys with similarfunctions should be grouped together. [Source: MIL-STD1472F, 1999]9.5.2.3 Arrange to facilitate task. The keyboardarrangement should provide ease of operation, minimizeuser training and retraining, and minimize ergonomicstress on the user. [Source: Kodak, 1983]9.5.2.4 Arranged for ease of use. Keyboards should bearranged so that the most frequently used keys are withineasy reach without requiring the user to reposition thehands (within the primary keying area). [Source: Douglas &Mithal, 1997]Additional information. Locating the most frequentlyused keys within the primary keying area allows the userto make the most of the keystrokes needed withoutmoving his or her hands and losing speed. Each time atouch typist moves his or her hands from the homelocation, it takes time to correctly reposition the handsbefore typing begins again (homing time).9.5.2.5 Destructive keys. Keys with negative orirreversible effects should be located so that inadvertentoperation is unlikely. [Source: NUREG 0700, 2002]Additional information. One way to minimize the chanceof inadvertent operation is to locate potentiallydestructive keys out of the primary keying area so thatthe user must move his or her hand to reach the key.9-16