  It is common for people to engage in information acquisition tasks while on
the move. To understand how users' visual behaviors influence microlearning, a
form of mobile information acquisition, we conducted a shadowing study with 8
participants and identified three common visual behaviors: 'glance', 'inspect',
and 'drift'. We found that 'drift' best supports mobile information
acquisition. We also identified four user-related factors that can influence
the utilization of mobile information acquisition opportunities: situational
awareness, switching costs, ongoing cognitive processes, and awareness of
opportunities. We further examined how these user-related factors interplay
with device-related factors through a technology probe with 20 participants
using mobile phones and optical head-mounted displays (OHMDs). Results indicate
that different device platforms significantly influence how mobile information
acquisition opportunities are used: OHMDs can better support mobile information
acquisition when visual attention is fragmented. OHMDs facilitate shorter
visual switch-times between the task and surroundings, which reduces the mental
barrier of task transition. Mobile phones, on the other hand, provide a more
focused experience in more stable surroundings. Based on these findings, we
discuss trade-offs and design implications for supporting information
acquisition tasks on the move.
