Pedrosa, R., "Perception-based design: including haptic feedback in expressive music interfaces", M.Sc. Thesis, University of British Columbia, 2007.
When designing haptic feedback into human-computer interfaces the most common approach is to restrict its deployment to only one of the haptic channels (either force or vibrotactile feedback) and this decision is often biased according to the technological boundaries imposed by the interface design or its purpose. The research presented here outlines a methodology developed to include haptic feedback in a gesture interface used to implement a computer based music instrument. The primary goal of this research is to achieve an increased understanding of how different flavors of haptic feedback should be combined to support both controllability and comfort in expressive interfaces such as computer based musical instruments. The work reported here has two parts: 1) a description of an initial user experiment conducted for the purpose of assessing the use of vibrotactile stimuli as rhythmic cues, and 2) a proposed research trajectory which will constitute the theme for a PhD project. The main hypothesis guiding this research is that the best way to include haptic feedback into any design should start by understanding the role each haptic channel plays in the "real life scenario". The assumption we will put into test is that the feedback provided for each haptic channel could be developed individually and later on fine tuned when mixed in the final design, and this includes that the addition of any extra cues we might be interested in supplying to the end user to enhance the real life experience should be designed and mixed in each haptic channel before the final blend occurs. This methodology could be defined as a "perception-based design": a design approach that starts with a perceptual characterization of the interaction that is being addressed and fine tune the results according to the perceptual load put on the user senses. We expect that the knowledge gathered will be useful not only to a broader spectrum of expressive interfaces but could also be extrapolated to including haptic feedback in other interface designs.