Human Factors Implications of Controlling User-Tool-Environment Interfaces

Abstract

When a person grasps an object, they create a hand-plus-object system. In perceiving properties of hand-held objects (including hand-held tools), people seem to show sensitivity to inertial variables relevant to the control of that object. Tool users demonstrate sensitivity to such variables in perceiving (1) whether a hand-held object could be used as a striking implement, (2) where an implement should be brought into contact with another object, and (3) where a hand-held object should be grasped so that object would be most effective as a striking implement. Importantly, tool users show task-specific sensitivity to inertial variables in each case depending on the functional constraints of the striking task (i.e., whether it emphasizes precision over power or vice versa). These findings may be relevant not only to the design of hand-held tools but also to the design of interfaces that allow the remote use of tools (e.g., telesurgery).