“…Sometimes many devices are used by one individual depending on the task at hand (Holtzman, 1999;Pascoe et al, 2000;Pham et al, 2000;Smailagic, 1999). For instance, in one application for field service engineers, devices used by each worker include a base unit the size of a laptop which is wirelessly connected to a remote server located in the home office, a cellular phone tethered to the base unit, a smaller removable satellite unit that replicates portions of the base unit display, and a wearable microphone that links to the cellular phone (Smailagic, 1999).…”