Ambiguous Goals During Human-Computer Interaction Induce Higher Mental Workload

摘要

Digitization of the working environment leads to tasks with high ambiguity, resulting in bad performance. The ambiguity of goals plays an important role in problem solving and could affect mental workload. In our study, we investigated whether goal ambiguity affects mental workload and task performance during planning. We hypothesized that problems with higher ambiguity require higher mental workload and degrade performance. The Tower of Hanoi (ToH) was employed and 21 participants were instructed to move disks in order to reach a particular goal state. The tower-ending goal state, where all disks had to be arranged on one peg, served as goal state with low ambiguity. The flat-ending goal state, where disks had to be arranged on different pegs, was considered as more ambiguous due to its less apparent goal structure. Mental workload was registered by means of the method of Dual Frequency Head Maps from the electroencephalogram. For evaluating subjects' performance, we registered the error rate and planning time. Analysis of the electroencephalogram yielded a significantly higher mental workload during the trials with a flat-ending goal state compared to trials with a tower-ending goal. Results of performance data were consistent with findings from the literature, indicating a higher error rate and longer planning time for the flat-ending goal state. By these, we gained proof that tasks with a higher level of goal ambiguity induce higher mental workload.