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

Keyboards June 20049.6.3.5 Consistent use. Fixed-function keys should bestandardized throughout the system and where possibleacross related systems. [Source: DOE-HFAC1, 1992; MIL-STD-1472F, 1999; NUREG 0700, 2002]• 9.6.3.6 Single activation. Fixed-function keys shall requireonly a single actuation to accomplish their function.[Source: NUREG 0700, 2002]9.6.3.7 Return to default. If the functions assigned to a setof function keys change as a result of user selection, theuser should be given an easy means to return to the defaultfunctions. [Source: NUREG 0700, 2002]9.6.3.8 Availability. Fixed-function keys should beselected to control functions that are continuouslyavailable; that is, the lock out of fixed-function keys shouldbe minimized. [Source: DOE-HFAC1, 1992, 1999; MIL-STD-1472F]9.6.3.9 Mechanical overlays. Mechanical overlays shouldnot be used to lock out function keys. [Source: DOE-HFAC1,1992; MIL-STD-1472F, 1999]• 9.6.3.10 Grouping. Fixed-function keys shall be groupedlogically and shall be placed in distinctive locations.[Source: DOE-HFAC1, 1992; MIL-STD-1472F, 1999; NUREG 0700,2002]• 9.6.3.11 Spatial relationships. Spatial relationships amongthe functions of the keys shall be reflected in the geometricrelationship of the keys. [Source: DOE-HFAC1, 1992; MIL-STD-1472F, 1999]Additional information. For example, a key that causes leftmovements should be located to the left of a key thatcauses right movement and a key that causes up movementshould be located above a key that causes down movement.9.6.3.12 Keyboard equivalents to function keys. If anapplication assigns operations to function keys, theoperations that can be performed with a function keyshould also be performable with alphanumeric keys.[Source: Keane (DISA HCISG V1.0), 1992]9-20