Transport Pilot Workload: A Comparison of Two Subjective Techniques

Abstract

Although SWAT and NASA-TLX workload scales have been compared on numerous occasions, they have not been compared in the context of transport operations. Transport pilot workload has traditionally been classified as long periods of low workload with occasional spikes of high workload. Thus, the relative sensitivity of the scales to variations in workload at the low end of the scale were evaluated. This study was a part of a larger study which investigated workload measures for aircraft certification, conducted in a Phase II certified Link/Boeing 727 simulator. No significant main effects were found for any performance- based measures of workload. However both SWAT and NASA-TLX were sensitive to differences between high and low workload flights and to differences among flight segments. NASA-TLX (but not SWAT) was sensitive to the increase in workload during the cruise segment of the high workload flight Between-subject variability was high for SWAT. NASA-TLX was found to be stable when compared in the test/retest paradigm. A test/retest by segment interaction suggested that this was not the case for SWAT ratings.

Get full access to this article

View all access options for this article.

References

Battiste

Bortolussi

M. R.

(in press). Assessment of Pilot Workload With The Introduction of An Airborne Threat-Alert System. Proceedings of the 1988 IEEE International Conference on Systems. Man, and Cybernetics. Anaheim, CA.

Biferno

M. A.

Boucek

, (1987). Volume I: Preliminary selection of measures. Proceeding of the Workshop on the Assessment of Crew Workload measurement Method, Techniques, and Procedures. Flight Dynamics Lab, Wright-Patterson AFB, OH.

Hart

S. G.

Hauser

J. R.

, (1987). Inflight application of three pilot workload measurement techniques. Aviation. Space and Environmental Medicine. 57, 402–410.

Hart

S. G.

Staveland

L. E.

, (1988). Development of NASA-TLX (Task Load Index): Results of empirical and theoretical research. In Hancock

P. A.

Meshkati (Eds.), Human Workload. Amsterdam: North Holland Press, 139–184.

Hayworth

L. A.

Bivens

C. C.

Shively

R. J.

(1987). An investigation of single-pilot advanced cockpit and control configurations for nap-of-the- earth helicopter combat mission task, n Proceedings of the 1986 Meeting of the American Helicopter Society. Washington, D.C., 657–672.

Nataupsky

Abbott

(1987). Comparison of workload measures on a computer-generated primary flight display. Proceedings of Human Factors Society 31th Annual Meeting (pp.548–552) Santa Monica, CA: Human Factors Society.

Reid

G. B.

Shingledecker

C. A.

Eggemeier

F. T.

(1981). Application of conjoint measurement to workload scale development. In the Proceedings of the Human Factors Society 25th Annual Meeting (pp. 522–526). Santa Monica, CA: Human Factor Society.

Sheridan

T. B.

Simpson

R. W.

(1979). Toward the definition and measurement of mental workload of transport pilots (Tech. Rep. No. FTL R79–4). Cambridge: MIT.

Silver

N. C.

Dunlap

W. P.

(1987). Averaging correlation coefficients: Should Fisher's transform be used? J. Applied Psychology. 72, 146–148.

10.

Vidulich

M. A.

Tsang

P. S.

(1985). Assessing subjective workload assessment: A comparison of Swat and NASA-bipolar methods, in Proceedings of Human Factors Society 29th Annual Meeting (pp. 71–75). Santa Monica, CA: Human Factors Society.