Towards an index of opportunity: Understanding in mental workload during task execution

Shamsi T. Iqbal, Piotr D. Adamczyk, Xianjun Sam Zheng, Brian P. Bailey

Research output: Chapter in Book/Report/Conference proceedingConference contribution


To contribute to systems that reason about human attention, our work empirically demonstrates how a user's mental workload changes during task execution. We conducted a study where users performed interactive, hierarchical tasks while mental workload was measured through the use of pupil size. Results show that (i) different types of subtasks impose different mental workload, (ii) workload decreases at subtask boundaries, (iii) workload decreases more at boundaries higher in a task model and less at boundaries lower in the model, (iv) workload changes among subtask boundaries within the same level of a task model, and (v) effective understanding of why changes in workload occur requires that the measure be tightly coupled to a validated task model. From the results, we show how to map mental workload onto a computational Index of Opportunity that systems can use to better reason about human attention.

Original languageEnglish (US)
Title of host publicationCHI 2005
Subtitle of host publicationTechnology, Safety, Community: Conference Proceedings - Conference on Human Factors in Computing Systems
PublisherAssociation for Computing Machinery
Number of pages10
ISBN (Print)1581139985, 9781581139983
StatePublished - 2005
EventCHI 2005: Technology, Safety, Community - Conference on Human Factors in Computing Systems - Portland, OR, United States
Duration: Apr 2 2005Apr 7 2005

Publication series

NameConference on Human Factors in Computing Systems - Proceedings
ISSN (Print)0274-9696


OtherCHI 2005: Technology, Safety, Community - Conference on Human Factors in Computing Systems
Country/TerritoryUnited States
CityPortland, OR


  • Attention
  • Interruption
  • Pupil size
  • Task models

ASJC Scopus subject areas

  • Industrial and Manufacturing Engineering

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