P-4　Investigation of the Optimal Interactive Methods for Natural User Interfaces

Abstract

The present study investigated the issues of performance and usability caused by joint-based interactive methods and CD gains with a Fitts task. Ten healthy participants performed multi-directional tapping tests with three joint-based interactive methods and three CD gains. The experimental results indicated that the joint-based interactive method and CD gain affected the performance indices and subjective usability ratings during a distal pointing task. The wrist-based interactive method is a better interactive method for tasks where pointing speed is the highest priority. The shoulder-based interactive method should be avoided in distal pointing tasks. The 1.7 CD gain, which was found to cause significantly higher MT and ER and lower TP and subjective usability rating scores than other two CD gains, should be avoided in distal pointing tasks. The elbow-based interactive method and 1.0 CD gain should be avoided when ID is higher than 5.79 bits; the shoulder-based interactive is only suggested for use when ID is less than 3.56 bits; and 1.7 CD gain is not suggested for use when ID is between 3.56 and 5.79 bits. Furthermore, the best suggested CD gain range for the wrist-based interactive method is a range of more than 1.0. The optimal CD gain setting of the elbow-based interactive method is 0.6, and the 1.0 CD gain is feasible for the shoulder-based interactive method.