Using augmented reality to train students to visualize three-dimensional drawings of mortise–tenon joints in furniture carpentry

Furniture carpentry uses spatial structure and geometry, e.g. mortise–tenon joints, which require cognitive judgments of hidden views and spatial understanding. For the furniture carpentry novice, the idea of spatial geometry in the mortise–tenon joint is difficult to understand because furniture carpentry drawings are usually two-dimensional (2-D) graphics. A great deal of cognitive effort and furniture design drawing practice is required to accurately visualize these 2-D objects as three-dimensional (3-D). Novices unfamiliar with 3-D spatial concepts often make mortise–tenon joint errors when making furniture. Augmented reality (AR) has helped train carpentry novices to understand the conceptual manifestations of 3-D space. In this study, we recruited 40 freshmen for a basic general carpentry class with an Experimental (n = 20) and a Control (n = 20) group. Both groups were asked to make, using their hands and a wood saw, mortise–tenon joints at three levels of difficulty: preliminary, mid-level, and advanced. The Experimental group was given AR training; the Control group was not. After the three phases had been completed, we found that the AR training helped Experimental group students improve their 3-D visualization and indirectly improved their grasp of furniture carpentry skills and of the complicated mortise–tenon joint structure.