Engineering topics

Vercruyssen, M.

Publications and source records attributed to Vercruyssen, M..

3 records

NASA NTRS1990

Workload and strategic adaptation under transformations of visual-coordinative mappings

A study involving a bimanual pursuit-tracking task is conducted to examine strategic exploration of differing visual and motor coordination patterns emphasizing workload as an indicator of strategic behavior. The mappings are conducted for 16 possible variations of order, speed, and combination. Performance is assessed by means of the rms and percent time-on-target, and the NASA task-load index is used to classify subjective reports on workload. The results are broken down into four primary performance mappings and four hybrid mappings called contradictory conditions. The order of difficulty of the conditions is apparently determined by the workload, except that in the case of the three most difficult decoupled conditions some dissociation is reported.

Caird, J. K.↗

NASA NTRS1989

The effects of practice on tracking and subjective workload

Six college-age male subjects performed one hundred, two-minute trials on a second-order tracking task. After each trial, subjects estimated perceived workload using both the NASA TLX and SWAT workload assessment procedures. Results confirmed an expected performance improvement on the tracking task which followed traditional learning curves within the performance of each individual. Perceived workload also decreased for both scales across trials. While performance variability significantly decreased across trials, workload variability remained constant. One month later, the same subjects returned to complete the second experiment in the sequence which was a retention replication of the first experiment. Results replicated those for the first experiment except that both performance error and workload were at reduced overall levels. Results in general affirm a parallel workload reduction with performance improvement, an observation consistent with a resource-based view of automaticity.

Hancock, P. A.↗

NASA NTRS1988

Estimation of duration and mental workload at differing times of day by males and females

Two experiments are reported which investigated whether male and female operator duration estimation and subjective workload followed conventional circadian fluctuation. In the first experiment, twenty-four subjects performed a filled time-estimation task in a constant blacked-out, noise-reduced environment at 0800, 1200, 1600, and 2000 h. In the second experiment, twelve subjects performed an unfilled time estimation task in similar conditions at 0900, 1400, and 1900 h. At the termination of all experimental sessions, participants completed the NASA TLX workload assessment questionnaire as a measure of perceived mental workload. Results indicated that while physiological response followed an expected pattern, estimations of duration and subjective perception of workload showed no significant effects for time-of-day. In each of the experiments, however, there were significant differences in durational estimates and mental workload response depending upon the gender of the participant. Results are taken to support the assertion that subjective workload is responsive largely to task-related factors and indicates the important differences that may be expected due to operator gender.

Hancock, P. A.↗