Supporting Multitasking: Evaluation of Novel Input and Output Characteristics to Support Primary and Secondary Task Performance Using Situation Awareness and Mental Workload

Abstract

Driving and flying are examples of tasks in dynamic process control environments where performing secondary tasks poses risks to the user, potentially resulting in detrimental effects on situation awareness (SA) and mental workload (MWL). The predominant theories of multitasking emphasize the potential of using alternate information processing channels to better support multitasking, and hence prompt the exploration of novel interface characteristics that may reduce cognitive and structural interference. This dissertation uses measures of SA and MWL to evaluate the potential of input and output display characteristics found in novel technologies, such as Google Glass, Pebble Smartwatch, and Windows Surface, to support multitasking performance. Three experiments were performed to evaluate the following input and output characteristics: voice input (Experiments 1 and 3), head-up display (Experiment 1), size of display (Experiments 2 and 3), use of discrete tactile signals (Experiment 2), and use of continuously informing tactile signals (Experiment 3). Experiments 1 and 2 altered only interface characteristics associated with secondary task performance, while Experiment 1 also altered interface characteristics associated with primary task performance in the attempt to more effectively redistribute MWL.

While Experiments 1 (Texting and Driving with Google Glass) and 2 (Weather Technology Characteristics in General Aviation Cockpits) indicate the potential SA and MWL benefits of using voice input and larger displays for secondary tasks in multitasking settings, Experiment 3 (Supporting Emergency Vehicle Mobile Command Terminal Use While Driving) sheds light on the limitations of these benefits with increasing task complexity. Experiment 1 showed that combining a head-up display with voice input provided additional marginal SA and MWL benefits. Experiment 2 also suggested SA and MWL benefits when using discrete tactile signals to aid in indicating the need for secondary task attentional shifts. Experiment 3 furthered this exploration of tactile signaling by presenting continuously informing vibrations relating to the primary task, exhibiting both the potential benefits of providing continuous information and the potential drawbacks of overreliance on such displays. These findings have the potential to fundamentally change the way users interact with technology by informing the development of and policies surrounding new products using these features.