The effect of unit task granularity on performance in teleoperations
Abstract
The choice of the command language in teleoperations has been left to systems designers, often resulting in arbitrary decisions. The granularity of the conmiand language (unit task granularity) is one of the factors that determines the level of interaction in teleoperations.
A 3-D computer simulation was used to test the effect of two levels of unit task granularity (high and low) on performance in nuclear material handling. Data on humanmachine performance, operator situation awareness, and operator workload were collected and studied. Results revealed that the operator workload and level 2 situation awareness was higher in high unit task granularity than in low unit task granularity. The analysis of the data under normal mode of operation revealed that the human-machine performance (as measured in terms of time and number of errors) was higher in low unit task granularity than in high unit task granularity. During system failure, human-machine performance was higher in high unit task granularity than in low unit task granularity.
This study revealed the trade-off between the performance under normal mode of operation and during system failure that is determined by the unit task granularity.