Augmented reality (AR) and virtual reality (VR) applications commonly employ interaction cues that denote to the user what interaction to take. In this paper, we present a Method for Analyzing the Grammar of Incomplete Cues (MAGIC), which provides an approach for evaluating the design of interaction cues based on the completeness or incompleteness of the functional grammar that they convey through perceptual stimuli. To demonstrate the importance of complete cues, we also present a user study investigating the effects of complete and incomplete cues on which interactions participants choose. The results indicate that incomplete cues do not afford sufficient information, so users make assumptions about the intended interactions. Furthermore, the results indicate that users are more likely to choose intended interactions when the cues are complete. Hence, we present MAGIC as a potentially useful tool for helping interaction designers avoid usability issues with incomplete interaction cues.

Target and steering-based techniques are two common approaches to travel in consumer VR applications. In this paper, we present two within-subject studies that employ a prior dual-task methodology to evaluate and compare the cognitive loads, travel performances, and simulator sickness of three common target-based travel techniques and three common steering-based travel techniques. We also present visual meta-analyses comparing our results to prior results using the same dual-task methodology. Based on our results and meta-analyses, we present several design suggestions for travel techniques based on various aspects of user experiences.