Evaluating 3D Visual Comparison Techniques for Change Detection in Virtual Reality

Change detection (CD) is critical in everyday tasks. While current algorithmic approaches for CD are improving, they remain imprecise, often requiring human intervention. Cognitive science research focuses on understanding CD mechanisms, especially through change blindness studies. However, these do not address the primary requirement in real-life CD - detecting changes as effectively as possible. Such a requirement is directly relevant to the visual comparison field - studying visualisation techniques to compare data and identify differences or changes effectively. Recent studies have used Virtual Reality (VR) to improve visual comparison by providing an immersive platform where users can interact with 3D data at a real-life scale, enhancing spatial reasoning. We believe VR could also improve CD performance accordingly. Particularly, VR offers stereoscopic depth perception over traditional displays, potentially enhancing the detection of spatial change. In this paper, we develop and analyse three 3D visual comparison techniques for CD in VR: Sliding Window, 3D Slider, and Switch Back. These techniques are evaluated under synthetic but realistic environments and frequently occurring Perceptual Challenges, including different Changed Object Size, Lighting Variation, and Scene Drift conditions. Experimental results reveal significant differences between the techniques in detection time measures and subjective user experience.