Long-distance couples face considerable communication challenges in their relationships. Unlike collocated couples, long-distance couples lack awareness cues associated with physical proximity and must use technologies such as SMS or telephony to stay in sync. We posit that long-distance couples have needs that are not met by prevailing communication technologies, which require explicit action from the sender as well as the receiver. We built CoupleVIBE to explore the properties of an implicit messaging channel and observe how couples would use such a technology.CoupleVIBE is a mobile application that automatically pushes a user's location-information to her partner's mobile phone via vibrotactile cues. We present qualitative results of a four-week user study, studying how seven couples used CoupleVIBE. A key result is that CoupleVIBE's implicit communication modality operated as a foundation that helps keep couples in sync, with other modalities being brought into play when further interaction was needed.

Abstract. Differences in perceptual and cognitive abilities between the young and elderly have implications for in-car tasks. As a primary example, although in-car navigation systems enhance situational awareness, this comes at the cost of increasing visual distraction and cognitive load. To address these shortcomings, this paper explores the efficacy of multi-modal cues for providing route guidance information. We present the results of a study evaluating the impact of multi-modal feedback on driving performance and cognitive load. We found that the full combination of visual, auditory, and haptic feedback was generally most useful to reduce way-finding errors. However, our study highlighted a number of differences between elder and younger drivers for their safer navigation. Adding more modalities strained the already high workload of elder drivers. In contrast, adding haptic feedback to traditional audio and visual feedback led to more attentive driving by younger drivers. Therefore, for elder drivers, navigation systems need to be personalized to enhance the benefit of auditory feedback without increasing the number of sensory feedbacks. For younger drivers, it is necessary to incorporate new nonvisual feedback to minimize distractions caused by visual feedback. We demonstrate these results through task performance-based measures, subjective workload measures and through objective workload measures that use psychophysiological responses of participants to predict a driver's cognitive load in near real-time.

Pico projectors attached to mobile phones allow users to view phone content using a large display. However, to provide input to projector phones, users have to look at the device, diverting their attention from the projected image. Additionally, other collocated users have no way of interacting with the device.We present ShadowPuppets, a system that supports collocated interaction with mobile projector phones. Shadow-Puppets allows users to cast hand shadows as input to mobile projector phones. Most people understand how to cast hand shadows, which provide an easy input modality. Additionally, they implicitly support collocated usage, as nearby users can cast shadows as input and one user can see and understand another user's hand shadows.We describe the results of three user studies. The first study examines what hand shadows users expect will cause various effects. The second study looks at how users perceive hand shadows, examining what effects they think various hand shadows will cause. Finally, we present qualitative results from a study with our functional prototype and discuss design implications for systems using shadows as input. Our findings suggest that shadow input can provide a natural and intuitive way of interacting with projected interfaces and can support collocated collaboration.