Perceived Time as a Measure of Mental Workload: Effects of Time Constraints and Task Success

Morten Hertzum, Kristin Due Holmegaard

Publikation: Bidrag til tidsskriftTidsskriftartikelForskningpeer review

Resumé

The mental workload imposed by systems is important to their operation and usability. Consequently, researchers and practitioners need reliable, valid, and easy-to-administer methods for measuring mental workload. The ratio of perceived time to clock time appears to be such a method, yet mental workload has multiple dimensions of which the perceived time ratio has mainly been linked to the task-related dimension. In this study, we investigate how the perceived time ratio is affected by time constraints, which make time an explicit concern in the execution of tasks, and task success, which is a performance-related rather than task-related dimension of mental workload. We find a higher perceived time ratio for timed than untimed tasks. According to subjective workload ratings and pupil-diameter measurements the timed tasks impose higher mental workload. This finding contradicts the prospective paradigm, which asserts that perceived time decreases with increasing mental workload. We also find a higher perceived time ratio for solved than unsolved tasks, while subjective workload ratings indicate lower mental workload for the solved tasks. This finding shows that the relationship between the perceived time ratio and mental workload is reversed for task success compared to time constraints. We discuss implications for the use of perceived time as a measure of mental workload.
OriginalsprogEngelsk
TidsskriftInternational Journal of Human-Computer Interaction
Vol/bind29
Udgave nummer1
Sider (fra-til)26-39
Antal sider14
ISSN1044-7318
DOI
StatusUdgivet - jan. 2013

Emneord

  • mental workload
  • perceived time
  • time estimation
  • time constraint
  • task success
  • evaluation methods

Citer dette

@article{9a215fac1c264d4087d816d0a93d7bd2,
title = "Perceived Time as a Measure of Mental Workload: Effects of Time Constraints and Task Success",
abstract = "The mental workload imposed by systems is important to their operation and usability. Consequently, researchers and practitioners need reliable, valid, and easy-to-administer methods for measuring mental workload. The ratio of perceived time to clock time appears to be such a method, yet mental workload has multiple dimensions of which the perceived time ratio has mainly been linked to the task-related dimension. In this study, we investigate how the perceived time ratio is affected by time constraints, which make time an explicit concern in the execution of tasks, and task success, which is a performance-related rather than task-related dimension of mental workload. We find a higher perceived time ratio for timed than untimed tasks. According to subjective workload ratings and pupil-diameter measurements the timed tasks impose higher mental workload. This finding contradicts the prospective paradigm, which asserts that perceived time decreases with increasing mental workload. We also find a higher perceived time ratio for solved than unsolved tasks, while subjective workload ratings indicate lower mental workload for the solved tasks. This finding shows that the relationship between the perceived time ratio and mental workload is reversed for task success compared to time constraints. We discuss implications for the use of perceived time as a measure of mental workload.",
keywords = "mental workload, perceived time, time estimation, time constraint, task success, evaluation methods",
author = "Morten Hertzum and Holmegaard, {Kristin Due}",
year = "2013",
month = "1",
doi = "10.1080/10447318.2012.676538",
language = "English",
volume = "29",
pages = "26--39",
journal = "International Journal of Human-Computer Interaction",
issn = "1044-7318",
publisher = "Taylor & Francis Inc.",
number = "1",

}

Perceived Time as a Measure of Mental Workload : Effects of Time Constraints and Task Success. / Hertzum, Morten; Holmegaard, Kristin Due.

I: International Journal of Human-Computer Interaction, Bind 29, Nr. 1, 01.2013, s. 26-39.

Publikation: Bidrag til tidsskriftTidsskriftartikelForskningpeer review

TY - JOUR

T1 - Perceived Time as a Measure of Mental Workload

T2 - Effects of Time Constraints and Task Success

AU - Hertzum, Morten

AU - Holmegaard, Kristin Due

PY - 2013/1

Y1 - 2013/1

N2 - The mental workload imposed by systems is important to their operation and usability. Consequently, researchers and practitioners need reliable, valid, and easy-to-administer methods for measuring mental workload. The ratio of perceived time to clock time appears to be such a method, yet mental workload has multiple dimensions of which the perceived time ratio has mainly been linked to the task-related dimension. In this study, we investigate how the perceived time ratio is affected by time constraints, which make time an explicit concern in the execution of tasks, and task success, which is a performance-related rather than task-related dimension of mental workload. We find a higher perceived time ratio for timed than untimed tasks. According to subjective workload ratings and pupil-diameter measurements the timed tasks impose higher mental workload. This finding contradicts the prospective paradigm, which asserts that perceived time decreases with increasing mental workload. We also find a higher perceived time ratio for solved than unsolved tasks, while subjective workload ratings indicate lower mental workload for the solved tasks. This finding shows that the relationship between the perceived time ratio and mental workload is reversed for task success compared to time constraints. We discuss implications for the use of perceived time as a measure of mental workload.

AB - The mental workload imposed by systems is important to their operation and usability. Consequently, researchers and practitioners need reliable, valid, and easy-to-administer methods for measuring mental workload. The ratio of perceived time to clock time appears to be such a method, yet mental workload has multiple dimensions of which the perceived time ratio has mainly been linked to the task-related dimension. In this study, we investigate how the perceived time ratio is affected by time constraints, which make time an explicit concern in the execution of tasks, and task success, which is a performance-related rather than task-related dimension of mental workload. We find a higher perceived time ratio for timed than untimed tasks. According to subjective workload ratings and pupil-diameter measurements the timed tasks impose higher mental workload. This finding contradicts the prospective paradigm, which asserts that perceived time decreases with increasing mental workload. We also find a higher perceived time ratio for solved than unsolved tasks, while subjective workload ratings indicate lower mental workload for the solved tasks. This finding shows that the relationship between the perceived time ratio and mental workload is reversed for task success compared to time constraints. We discuss implications for the use of perceived time as a measure of mental workload.

KW - mental workload

KW - perceived time

KW - time estimation

KW - time constraint

KW - task success

KW - evaluation methods

U2 - 10.1080/10447318.2012.676538

DO - 10.1080/10447318.2012.676538

M3 - Journal article

VL - 29

SP - 26

EP - 39

JO - International Journal of Human-Computer Interaction

JF - International Journal of Human-Computer Interaction

SN - 1044-7318

IS - 1

ER -