Subjects have certain expectations about the mapping of motion directions of the control device on those of the controlled object on the accompanying display. When the actual mapping is according to this expectation, the relation is compatible. Compared to less compatible or even incompatible relations, less training is required, reaction times are faster, less errors are made, and mental workload is lower in compatible control-display relations. Concerning this mapping of motns of device and controlled object (motion compatibil-ity), a lot of research is conducted on configurations with only one or two degrees of freedom, in contrast with devices and displays with three or more degrees of freedom. Motion compatibility in 3D may be based on two different principles: spatial-motion mapping, and reference-plane mapping. In the first principle, motions of the device in space are always parallel to the motions of the object in the display. In the second, the plane of the device was used as reference plane for the display, and projected on the display as such. The present experiment investigates the effects of presence and absence of both mapping principles in a 3D positioning task. The results showed a positive main effect of reference-plane mapping, while no main effect of spatial-motion mapping, nor an interaction between both was found. The experimental task was executed faster and more efficient, and the task was learned faster in the reference-plane mapppping conditions. These results indicate that motion compatibility between control and display with three degrees of freedom is mainly determined by motions in relation to (different) planes, and not to the 3D space as such. Motions in relation to the plane of the device are projected onto the plane of the display.
Onderzoek naar bewegingscompatibiliteit bij een 3D positioneringstaak laat zien dat proefpersonen het projecteren van muisvlak op beeldschermvlak prefereren boven een configuratie waarbij bewegingen van cursor en bedieningsmiddel parallel lopen.