In Augmented Reality (AR), search performance for outdoor tasks is an important metric for evaluating the success of a large number of AR applications. Users must be able to find content quickly, labels and indicators must not be invasive but still clearly noticeable, and the user interface should maximize search performance in a variety of conditions. To address these issues, we have set up a series of experiments to test the influence of virtual characteristics such as color, size, and leader lines on the performance of search tasks and noticeability in both real and simulated environments. The first experiment showed that limited FOV will severe-ly limit search performance, but that appropriate placement of labels and leaders within the periphery can alleviate this problem without interfering with walking or decreasing user comfort. In the second experiment, we found that different types of motion are more no-ticeable in optical versus video see-through displays, but that blue coloration is most noticeable in both. Results can aid in designing more effective view management techniques, especially for wider field of view display.
A wide field of view augmented reality display is a special type of head-worn device that enables users to view augmentations in the peripheral visual field. However, the actual effects of a wide field of view display on the perception of augmentations have not been widely studied. To improve our understanding of this type of display when conducting divided attention search tasks, we conducted an in depth experiment testing two view management methods, in-view and in-situ labelling. With in-view labelling, search target annotations appear on the display border with a corresponding leader line, whereas in-situ annotations appear without a leader line, as if they are affixed to the referenced objects in the environment. Results show that target discovery rates consistently drop with in-view labelling and increase with in-situ labelling as display angle approaches 100 degrees of field of view. Past this point, the performances of the two view management methods begin to converge, suggesting equivalent discovery rates at approximately 130 degrees of field of view. Results also indicate that users exhibited lower discovery rates for targets appearing in peripheral vision, and that there is little impact of field of view on response time and mental workload.
