Haptically creating affordances: the user-tool interface.
Successful use of a hand-held tool requires overcoming the rotational inertia of the hand-plus-tool system. Where an object is grasped affects this rotational inertia. Appropriate choice of grip position may be crucial in the safe, effective, and efficient control of a hand-held tool. In 3 experiments, the authors investigated how choice of grip position on a tool was constrained by task demands. The results suggest that choice of grasp position serves to establish relationships among 3 variables derived from the inertial ellipsoid of the hand-object system (volume, symmetry, and eigenvector angle) in a way that specifically reflected the power or precision constraints of the given task. These variables have previously been shown to play a role in haptic perception of tool function. Changing grasp position on a tool is a way to exert control over the nuances of the user-tool interface.
Department of Psychology, University of Connecticut, CT, USA. jeffreywagman@ilstu.edu
Jeffrey B
JB
Wagman
Claudia
C
Carello
D002755:Choice Behavior; D004777:Environment; D005403:Fixation, Ocular; D018737:Hand Strength / Q000502:physiology; D006801:Humans; D012399:Rotation; D014584:User-Computer Interface; D014796:Visual Perception