An empirical comparison of use-in-motion evaluation scenarios for mobile computing devices

Comparing evaluation methods for encumbrance and walking on interaction with touchscreen mobile devices

“…One common method to evaluate the impact of mobility is to use a treadmill [3,4,13]. The user sets the preferred pace on the treadmill by estimating PWS.…”

“…As an alternative, researchers have replicated real world settings by creating walking routes indoors [3,14,25] and outdoors [5,12,13] for users to navigate. Some studies [3,14,15] have also added obstacles to the walking path to increase the user's cognitive workload. Barnard et al [3] varied room illumination to simulate realistic lighting changes to reproduce "an actual user experience" when comparing treadmill and ground walking.…”

“…Some studies [3,14,15] have also added obstacles to the walking path to increase the user's cognitive workload. Barnard et al [3] varied room illumination to simulate realistic lighting changes to reproduce "an actual user experience" when comparing treadmill and ground walking. In the mobile study by Mackay et al [16], users were instructed to stop walking and stand still at random intervals to replicate scenarios where the user is suddenly interrupted.…”

“…Each participant's PWS on the treadmill was recorded before the experiment began and was measured by increasing the speed of the treadmill at 0.1 km/h increments up to the speed the user would normally walk. Like Barnard et al [3] and Bergstrom et al [4], participants were asked to think about the speed he/she would usually walk while not in a hurry when estimating the PWS. Once the PWS was recorded, the experimenter adjusted the pace accordingly for all the treadmill conditions for each participant.…”

“…In previous studies, two broad methods have been used to examine the effects of mobility on input performance with handheld devices: 1) walking on a treadmill [3,4] and 2) walking around a predefined route [3,13,25]. Barnard et al [3] compared both methods and reported the advantages and limitations of each to examine the impact of walking on interactions with mobile devices. However, it is unclear if the two approaches are still appropriate to examine the effects of encumbrance while the user is on the move.…”