  Augmented reality (AR) is emerging in visual search tasks for increasingly
immersive interactions with virtual objects. We propose an AR approach
providing visual and audio hints along with gaze-assisted instant post-task
feedback for search tasks based on mobile head-mounted display (HMD). The
target case was a book-searching task, in which we aimed to explore the effect
of the hints together with the task feedback with two hypotheses. H1: Since
visual and audio hints can positively affect AR search tasks, the combination
outperforms the individuals. H2: The gaze-assisted instant post-task feedback
can positively affect AR search tasks. The proof-of-concept was demonstrated by
an AR app in HMD and a comprehensive user study (n=96) consisting of two
sub-studies, Study I (n=48) without task feedback and Study II (n=48) with task
feedback. Following quantitative and qualitative analysis, our results
partially verified H1 and completely verified H2, enabling us to conclude that
the synthesis of visual and audio hints conditionally improves the AR visual
search task efficiency when coupled with task feedback.
