How Do People Use Their Mobile Phones?: A Field Study of Small Device Users

The usability evaluation of small devices (i.e., mobile phones and PDAs) is an emerging area of research. Compared with desktop computers, designing a usability evaluation for small devices is more challenging. Context of use, such as environmental disturbance and a user’s physical activities affect the evaluation results. However, these parameters are usually ignored or excluded from simple and unnatural evaluation settings; therefore generating unrealistic results. This paper presents a field study that investigates the behaviour of small device users in naturalistic settings. The study consists of a series of unobtrusive remote observations and interviews. Results show that small device users normally use the device with just one hand, press the keys with thumb and make phone calls and send text messages while walking. They normally correct typing errors and use abbreviations. On average, small device users switch their attention between the device screen and the surrounding environment 3 times every 20 seconds, and this increases when they are walking.