Motor-Intuitive Interactions Based on Image Schemas: Aligning Touchless Interaction Primitives with Human Sensorimotor Abilities

Elicitation and evaluation studies investigated intuitiveness of touchless gestures but did not operationalize intuitiveness. For example, studies found that users fail to make accurate 3D strokes as interaction commands. But this phenomenon remains unexplained. In this paper, we first explain how making accurate 3D strokes is generally unintuitive, because it exceeds our sensorimotor knowledge. We then introduce motor-intuitive, touchless interaction that uses sensorimotor knowledge by relying on image schemas. Specifically, we propose an interaction primitive—mid-air, directional strokes—based on space schemas up–down and left–right. In a controlled study with large displays, we found that biomechanical factors affected directional strokes. Strokes were efficient (0.2 s) and effective (12.5° angular error), but affected by directions and length. Our work operationalized intuitive touchless interaction using the continuum of knowledge in intuitive interaction, and demonstrated how user performance of a motor-intuitive, touchless primitive based on sensorimotor knowledge (image schemas) is affected by biomechanical factors.