Interface Design and Spatial Cognition: A Case of Virtual Molecule Manipulation

Interface Design and Spatial Cognition: A Case of Virtual Molecule Manipulation Trevor J. Barrett (trevor.barrett@psych.ucsb.edu) Department of Psychological and Brain Sciences, UCSB Santa Barbara, CA 93106 USA Mary Hegarty (mary.hegarty@psych.ucsb.edu) Department of Psychological and Brain Sciences, UCSB Santa Barbara, CA 93106 USA Klatzy, Wu, & Stetten (2008) suggest that more perceptually mediated interfaces allow for better performance over cognitively mediated interfaces. Perceptually mediated interfaces decrease demand on spatial working memory, thereby freeing up cognitive resources to allocate to performance or learning. If stereo and colocation increase perceptual mediation, decrease spatial cognitive load, and allow for additional cognitive recourses to be devoted to performance, then participants should show faster and more accurate performance when these cues are provided. Abstract Virtual models are a common instructional tool used in chemistry education to help students learn about the 3D structure of molecules. The present study examined effects of two interface design features on participant performance during a molecule orientation task. The features examined were 1) colocation of the visual and haptic workspace and 2) stereoscopic viewing. The results indicate that colocating the interface increased participant accuracy, while providing stereo did not. Neither factor affected response time. The effects of colocation were also reflected in subjective ratings of task demand measured by the NASA-TLX. Spatial ability was predictive of task performance but did not interact with interface effects. The findings are discussed in the context of spatial cognition and interface design for manipulating virtual objects. Stereo and Colocation Technology Both stereo and colocation technologies have been shown to increase speed and accuracy in virtual object manipulation tasks (Ware & Rose, 1999, Arsenault & Ware, 2004, Klatzky et al., 2008), however some studies have shown no significant effect of stereo (Khooshabeh & Hegarty, 2010) or colocation (Liere, 2005). It is important to note that the majority of studies investigating performance with these technologies have used object translation tasks, rather than a rotation task as in the current study. In general, we should be cautious in generalizing specific interface design effects across various tasks, as different perceptual cues may be important for supporting rotation and translation. To our knowledge, no study has investigated the effects of varying both stereo and colocation during a virtual object rotation task in the same experiment. The results of the present study will help to elucidate the importance of these cues for increasing perceptual mediation and decreasing cognitive load in a task that involves virtual object rotation. Keywords: spatial cognition; interface; virtual; rotation; stereoscopic; colocation; organic chemistry Computer-based virtual models are becoming an increasingly common instructional medium in science, technology, engineering, and mathematics (STEM) education (Trindade, Fiolhais & Almeida, 2002). Virtual learning environments have shown promise in fostering meaningful learning, but virtual models vary considerably in the perceptual cues and interfaces that they provide so there is still much to be understood regarding how to best design and implement these technologies. For example, current stereoscopic displays are more expensive and less available, so it is important to know whether they provide a benefit to performance and learning outcomes, or whether monoscopic displays are as effective. The present study aims to understand the relative value of two factors on which virtual displays vary, (1) colocating the hand-held interface and the displayed virtual image (colocation), and (2) providing stereoscopic 3D viewing (stereo) for a representation matching task in organic chemistry. Stull, Barrett, & Hegarty (2012), found participants performed this task with greater efficiency using a virtual model system (with stereoscopic display and colocation of visual and haptic workspaces) than when using standard concrete models. Given this efficiency advantage, a goal of this study is to investigate the relative importance of providing stereo and colocation during a virtual object manipulation task. Organic Chemistry as a Test-bed Organic chemistry is a domain rich in spatial representation; diagrams and models of 3D molecular structures are ubiquitous in instruction as well as in cutting edge research environments. Understanding molecular structure is an essential skill all organic chemists must have in order to learn, research, and communicate their science. Diagrams and models serve as a language of spatial connections and structures and therefore are vital in developing understanding of structures and making advancements in the field (Kozma & Russell, 2005).