Illustrative evaluation index for haptic interfaces using confusion matrices

For researchers of haptic interfaces, evaluation of the perceptual similarity between virtual and real haptic stimuli has long been a serious problem. One of the most commonly employed evaluation methods is an identification task where assessors identify the type of randomly presented stimuli among multiple candidates. The results of this method are summarized as confusion matrices. We developed a method that allocates all virtual and real stimuli in a perceptual space. The spatial distribution of the stimuli allows us to visually understand the perceptual relationships between the stimuli. A brief validation confirmed that the proposed method is effective in evaluating the perceptual similarity between virtual and real stimuli.