8. Conclusion

A combined physical and psychophysical experimental methodology is proposed in this book. First, the existing physical performance measures and device characterization techniques were investigated and described in an illustrative way. The physical characterization methods were demonstrated on a two degrees-of-freedom haptic interface. Second, a wide range of human psychophysical experiments were reviewed and the appropriate ones were applied to haptic interactions. The psychophysical experiments were unified as a systematic and complete evaluation method for haptic interfaces. Seven psychophysical tests were derived and implemented for three commercial force-feedback devices. Experimental user studies were carried out and applicability of the tests to a tactile feedback device was investigated. This chapter summarizes the contributions and provides a synthesis of the physical and psychophysical evaluation methods.