Small-device users situationally impaired by input

Users of small computational devices, such as Mobile telephones or Personal Digital Assistants, are situationally impaired by both the device and the context of the device's use. This paper describes empirical work which makes the link between the behaviour of motor impaired desktop users and non-impaired users of small-devices. This is important because it may, therefore, be possible to leverage existing solutions for motor-impaired users into the small-device domain. We find that there is significant overlap in the extent of the problems encountered, but not the magnitude. Eight of the 11 existing errors made by motor-impaired users were also present in our small-device study in which two additional error types, key ambiguity and landing errors, were also observed. In addition, small-device rates for common error types were higher than those of desktop users with no impairment, but lower than those of desktop users with motor impairments. We suggest that this difference is because all users were seated to maintain constancy between studies and assert that this magnitude difference will equalise once the small-device is used in a mobile context. © 2009 Elsevier Ltd. All rights reserved.