Tracking in Two Dimensions as a Function of Dimension Priorities and Tracking Difficulty (II).

摘要

Major issues in this study are the degree of voluntary control the operator has on his resources, his ability and willingness to meet demands set by the experimentor, and the extent to which resource allocation affects joint performance in various task combinations and different difficulty manipulations. An experiment is presented in which each of the dimensions (horizontal and vertical) in a two dimensional tracking task was treated as a separate time-shared task, and manipulated independently. Tracking accuracy was assessed under a joint manipulation of target frequency on each dimension and their relative priorities. The results showed that the priority variable had the most robust effect on performance. However, this effect was negatively accelerated. Subjects degraded performance on an axis when its priority was reduced, but the released resources could not be effectively transferred to improve performance on the high priority axis. Several interpretations for these results are discussed. The most challenging one suggests that the two dimensions mainly require different types of resources. Manipulations of target frequency yield only small, though reliable, effects. (Author)