טכניון מכון טכנולוגי לישראל
הטכניון מכון טכנולוגי לישראל - בית הספר ללימודי מוסמכים  
Ph.D Thesis
Ph.D StudentKahana Allon
SubjectWork Load Measurement as an Indicator of Team Interaction
Style during Complex Task Execution
DepartmentDepartment of Industrial Engineering and Management
Supervisor Professor Emeritus Daniel Gopher


Abstract

The present study seeks to further investigate characteristics of effective teams by measuring the physiological indicators of mental work load of pilots during flight. Ten crews of two pilots each flew two experimental flight missions on a commercial aircraft simulator. Sustained mental load measurements taken during standard and eventful flights indicate that the pilot taking the role of Pilot Not Flying (PNF) experienced higher workload regardless of his rank (captain or first officer). In addition, post events dynamic mental load measures show that the captain of the flight experience higher workload regardless of the in-flight role. Together, these finding predict unbalanced load distribution within teams where the captain serve as PNF during standard or eventful flights, and indicate that despite the attempt to equally distribute task demands, one crew member experiences a greater degree of mental workload than his crew member.

Furthermore, a significant correlation was found between the ability of the crew to equally distribute workload, and its overall performance. The shorter the unequal load distribution events were, the better the team performed. Teams that divided workload equally among its members performed better and experienced less overall mental load.

The present study compared four physiological measurement techniques of mental load: Heart Rate (HR), Heart Rate Variability (HRV), Pupil Dilation (PD) and Peripheral Arterial Tone (PAT). Results indicate that the PAT technique is the most sensitive to sustained mental load as well as to event related load. Although its reaction time to unexpected events was somewhat slower compared to the Pupil Diameter technique, it is more suitable for measuring of mental workload within an operational environment.