Fitts' Law with a Virtual Reality Glove and a Mouse: Effects of Gain

The effects of gain on target acq uI sItion using the classic FillS' law paradigm with a mouse and a virtual reality glove were tested. The mouse was significantly faster and had significantly lower error rates. For both devices , increased gain decreased movement times. Errors and movement times increased for both devices as the index of difficulty increased . Target entries were found to be significantly higher for the mouse. A model is proposed whereby gain has an inverse multiplicative effec t upon Fitts' index of difficulty. The model accounts for 81 % of the mouse's variance and 48% of the glove's variance. The lower number for the glove shows that Fitts' law has difficulties predicting its performance. The glove appeared not to operate at Fitts' law's prediction s when gain was greater than one. The implications for the design of cyberspaces are discussed.