Labeling Out-of-View Objects in Immersive Analytics to Support Situated Visual Searching

TL;DR

This study explores effective labeling techniques for out-of-view objects in AR to enhance visual search, finding that angle-encoded labels with directional cues improve performance and user satisfaction.

Contribution

The paper introduces and evaluates three novel visualization techniques for labeling out-of-view objects in AR, advancing AR interface design for visual search tasks.

Findings

Angle-encoded labels with directional cues perform best.

Out-of-view labels aid in spatial orientation and object comparison.

Spatially sparse object search benefits from out-of-view labeling.

Abstract

Augmented Reality (AR) embeds digital information into objects of the physical world. Data can be shown in-situ, thereby enabling real-time visual comparisons and object search in real-life user tasks, such as comparing products and looking up scores in a sports game. While there have been studies on designing AR interfaces for situated information retrieval, there has only been limited research on AR object labeling for visual search tasks in the spatial environment. In this paper, we identify and categorize different design aspects in AR label design and report on a formal user study on labels for out-of-view objects to support visual search tasks in AR. We design three visualization techniques for out-of-view object labeling in AR, which respectively encode the relative physical position (height-encoded), the rotational direction (angle-encoded), and the label values (value-encoded) of the objects. We further implement two traditional in-view object labeling techniques, where labels are placed either next to the respective objects (situated) or at the edge of the AR FoV (boundary). We evaluate these five different label conditions in three visual search tasks for static objects. Our study shows that out-of-view object labels are beneficial when searching for objects outside the FoV, spatial orientation, and when comparing multiple spatially sparse objects. Angle-encoded labels with directional cues of the surrounding objects have the overall best performance with the highest user satisfaction. We discuss the implications of our findings for future immersive AR interface design.