Human Factors Criteria for the Design and Acquisition of ... - FAA
Human Factors Criteria for the Design and Acquisition of ... - FAA
Human Factors Criteria for the Design and Acquisition of ... - FAA
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Keyboards June 2004Exhibit 9.12.g Vertical Split keyboardNon-keyboard alternatives:Chord keyboards –Chord keyboards are smaller, generallyone-h<strong>and</strong>ed keyboards, that require <strong>the</strong> user to activate twoor more keys simultaneously to produce a single input unit.Common uses <strong>for</strong> chord keyboards are <strong>for</strong> stenographers,some mail sorting machines, <strong>and</strong> <strong>for</strong> people with disabilities.Advantages to <strong>the</strong> chord keyboards are that trained users canreach data entry rates even higher than with traditionalkeyboards; <strong>the</strong>y are small; <strong>and</strong> most can be used by oneh<strong>and</strong>. There are also potential ergonomic advantages <strong>of</strong>assigning <strong>the</strong> most frequently used keys to <strong>the</strong> strongest, leastfatigue-prone fingers.Chord keyboards were found to be superior to traditionalkeyboards <strong>for</strong> mail sorting tasks; however, chords can bedifficult to learn <strong>and</strong> execute. Additionally, chord keyboards<strong>of</strong>ten require a means <strong>of</strong> interpreting <strong>the</strong> data entry. As <strong>the</strong>need <strong>for</strong> data entry is currently being filled by traditionalkeyboards, it is not likely that chord keyboards will bewidely adopted <strong>for</strong> Federal Aviation Administration use.[Source: Conrad & Longman, 1965; Gopher et al., 1985; Greenstein &Muto, 1988; Lu & Aghazadeh, 1992; McAlindon, 1994; McCormick,1976 cited in Baber, 1997; Noyes, 1983; Siebel, 1962]9-34
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