title: Measuring workload in collaborative contexts: trait versus state perspectives.
abstract: OBJECTIVE
  In the present study, we explored the state versus trait aspects of measures of task and team workload in a disaster simulation.
  
  
  BACKGROUND
  There is often a need to assess workload in both individual and collaborative settings. Researchers in this field often use the NASATask Load Index (NASA-TLX) as a global measure of workload by aggregating the NASA-TLX's component items. Using this practice, one may overlook the distinction between traits and states.
  
  
  METHODS
  Fifteen dyadic teams (11 inexperienced, 4 experienced) completed five sessions of a tsunami disaster simulator. After every session, individuals completed a modified version of the NASA-TLX that included team workload measures.We then examined the workload items by using a between-subjects and within-subjects perspective.
  
  
  RESULTS
  Between-subjects and within-subjects correlations among the items indicated the workload items are more independent within subjects (as states) than between subjects (as traits). Correlations between the workload items and simulation performance were also different at the trait and state levels.
  
  
  CONCLUSIONS
  Workload may behave differently at trait (between-subjects) and state (within-subjects) levels.
  
  
  CONCLUSIONS
  Researchers interested in workload measurement as a state should take a within-subjects perspective in their analyses.
authors.forename: William S
authors.initials: WS
authors.lastname: Helton
authors.forename: Gregory J
authors.initials: GJ
authors.lastname: Funke
authors.forename: Benjamin A
authors.initials: BA
authors.lastname: Knott
mesh_terms: D000328:Adult; D004189:Disaster Planning; D005163:Factor Analysis, Statistical; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D011594:Psychometrics / Q000295:instrumentation / Q000379:methods*; D013647:Task Performance and Analysis; D057192:Tsunamis; D016526:Workload / Q000523:psychology; D055815:Young Adult