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

Keyboards June 20049.5.1.6 Keyboard thickness. The thickness of a keyboard(base to home row of keys) should be between 38 mm(1.50 in) and 70 mm (2.76 in) as long as the overallkeyboard, plus work surface, height is adequate for the userto maintain proper posture and there is adequate kneeclearance under the work surface. See Exhibit 9.5.1.6.[Source: Burke, Muto & Guzman, 1984; Emmons & Hirsch, 1982;Miller & Suther, 1981].Exhibit 9.5.1.6 Keyboard thicknessHome rowKeyboard thicknessBaseAdditional information. The height of the home row ofkeys (thickness of the keyboard) itself is mainly based onpreference rather than performance. However, the overallheight of the keyboard in relation to the floor (inclusive ofthe keyboard support) can have ergonomic implications.Preferred keyboard thickness tends to be interrelated withkeyboard slope and the overall height of the keyboard pluswork surface in relation to the floor. [Source: Burke et al.,1984; Emmons & Hirsch, 1982; Hunting et al., 1981; Miller & Suther,1981]• 9.5.1.7 Home row locator. The F and J keys on thealphanumeric keyboard and the number 5 key on thenumeric keypad shall have a tactile feature to assist theusers in positioning their fingers on the home row of thekeyboard, preferably a small raised bar or spot on the keycap. [Source: Scadden & Vanderheiden, 1988]9-12