ABSTRACT
This chapter introduced central concepts in haptics research and fundamental psychophysical techniques that are used to investigate how the haptic system works. The most common psychophysical paradigms which are used to investigate absolute and difference thresholds of the human haptic system are the adjustment, constant stimuli and staircase methods. In order to determine what type of physical information is important and understand how the haptic system gathers this information, researchers use a variety of methods and tools. The advantage of a good haptic interface is that it can generate a continuum of stimulus values instantly and on demand. The single-point contact nature of these devices limits their ability to engage the haptic system in a natural manner. Perception of surface orientation is a fundamental ability of the haptic system since it is involved in both shape perception and object manipulation.
