DIN EN ISO 9241-420:2011-10

Input devices provide the means for users to enter data into interactive systems. Generally speaking, an input device is a sensor that can detect changes in user behaviour (for instance, gestures, moving fingers, etcetera) and transform them into signals to be interpreted by the interactive system. This part of ISO 9241 offers guidance for the selection of input devices for interactive systems, based on ergonomic factors, considering the limitations and capabilities of users and the specific tasks and context of use. It describes methods for selecting a device or a combination of devices for the task at hand. It can also be used for evaluating the acceptability of trade-offs under the existing conditions. The target users of this part of the standard are user organizations and systems integrators who tailor systems for a given context of use. It is applicable to the following input devices: keyboards, mice, pucks, joysticks, trackballs, trackpads, tablets and overlays, touch-sensitive screens, styli and light pens. It does not specify design requirements or give recommendations for those devices. The selection guidance in this document has been developed for the single-finger use of touchpads. Touchpads that allow the use of more fingers do exist, but this part does not offer any guidance on their selection. The only physical component of a speech-recognition system is a microphone. Without proper knowledge of the context of use it is not possible to give guidance for selection. This first edition of ISO 9241-420, together with ISO 9241-400, ISO 9241-410 and ISO/TS 9241-411, partially replaces ISO 9241-4:1998 and ISO 9241-9:2000. ISO 9241-420 has been prepared by Technical Committee ISO/TC 159, Subcommittee SC 4 "Ergonomics of human-system interaction", Working Group WG 3 "Controls, workplace and environmental regulations", in collaboration with Technical Committee CEN/TC 122 "Ergonomics", the secretariat of which is held by DIN (Germany). The responsible German committee is NA 023-00-04 GA "Ergonomie für Informationsverarbeitungssysteme" ("Ergonomics for information processing systems") at the Ergonomics Standards Committee (NAErg).