Go to the NASA Homepage
Search >
Click to Search
Human Systems Integration Division homepageHuman Systems Integration Division homepage Organization pageOrganization page Technical Areas pageTechnical Areas page Outreach and Publications pageOutreach and Publications page Contact pageContact page
Human Systems Integration Division Homepage
Outreach & Publications Sidebar Header
Go to the Outreach & Publications pageGo to the Outreach & Publications page
Go to Awards pageGo to Awards page
Go to News pageGo to News page
Go to Factsheets pageGo to Factsheets page
Go to Multimedia pageGo to Multimedia page
Go to Human Factors 101 pageGo to Human Factors 101 page
What is Human System Integration? Website
Publication Header
A Non-Linear Relationship between Controller Workload and Traffic Count  (2005)
Abstract Header
Controller workload has been a focal topic in air traffic management research because it is considered a key limiting factor to capacity increase in air traffic operations. Because workload ratings are subjective and highly prone to individual differences, some researchers have tried to replace workload with more objective metrics, such as aircraft count. A significant caveat in substituting these metrics for workload ratings, however, is that their relationships are non-linear. For example, as the number of aircraft increases linearly, the controller's perceived workload jumps from low to high at a certain traffic threshold, resulting in a step- function increase in workload with respect to aircraft count, suggesting that controllers perceive workload categorically. The non-linear relationship between workload and aircraft count has been validated using data collected from a recent study on the En Route Free Maneuvering concept element (Lee, Prevot, Mercer, Smith, & Palmer, 2005). The results suggest that objective metrics, such as aircraft count, may not be used interchangeably with subjective workload. In addition, any estimation on workload should not be extrapolated from a set of workload measures taken from an experiment since the extrapolated workload is likely to significantly underestimate workload.
Private Investigators Header
Authors Header
Groups Header
Keywords Header
Controller, Count, Non-Linear, Relationship, Traffic, Workload
References Header
49th Annual Meeting of Human Factors and Ergonomics Society, Orlando, FL
Download Header
Adobe PDF Icon  HFES2005_Lee.pdf (Download Acrobat Reader Click to download Adobe Acrabat Reader)
  (91KB) (application/pdf)
Go to the First Gov Homepage
Go to the NASA - National Aeronautics and Space Administration Homepage
Curator: Phil So
NASA Official: Alonso Vera
Last Updated: August 15, 2019