Balancing Awareness and Interruption in Mobile Patrol using Context-Aware Notification

In mobile computing, a fundamental problem is maintaining awareness of the environment and of information presented as messages on a mobile device. In mobile police patrol, officers need to pay attention to their direct environment and stay informed of incidents elsewhere. To prevent unwanted interruption, a context-aware notification system adapts the timing and appearance of incident messages, based on user activity (available, in transit or busy) and message priority (high, normal or low). We evaluated the benefits and costs of adaptive notification compared to three uniform notification styles (presenting full messages, postponing messages or presenting indicators). Thirty-two trained student participants used a prototype notification system in a controlled mobile patrol task. The results were validated in a follow-up study with twenty-four police officers. We found that full messages elicited a quick, but sometimes incorrect response to incident messages, whereas with adaptive notification responses were slower but only for lower priority messages. The results are discussed in view of notification systems’ design for mobile professionals.