Monotony: a critical state in ATC

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Monotony a critical state in ATC - and a
neglected phenomena
Sonja Straussberger University of
Graz/EUROCONTROL Experimental Center K.
Wolfgang Kallus Institute of Psychology,
University of Graz, Austria Dirk
Schaefer EUROCONTROL Experimental Center, France
Human Factors in Aviation Current Research and
Developments in the Austrian Aviation Psychology
Association Graz, 21.3.2006
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Introduction
Air Traffic Control
Is there monotony?
Straussberger, S., Kallus, K.W. Schäfer, D.
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Introduction
Research Challenges

• Highly increasing traffic expected
• Future ATM concepts (e.g. traffic flow
  synchronization) and further automation (e.g.
  data link) change operator requirements
• Areas and periods of high AND low traffic
  density/ complexity
• Homogeneity and Repetition clearly represented in
  EUROCONTROL approaches
• BUT Monotony not well researched

Straussberger, S., Kallus, K.W. Schäfer, D.
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Introduction
Research Background

• Ill-defined and mixed terms
• Monotony (e.g., McBain, 1970)
• Boredom (e.g., Mikulas Vodanovich, 1993)
• Underload (e.g., Young Stanton, 2002)
• Contributing factors
• Task Characteristics (e.g., Pfendl, 1985)
• Individual Factors (e.g., Hill, 1975)
• Situational Factors (e.g., Marvje Horne, 1994)
• Short-term and long-term impairments
• (e.g., Thackray, 1975 Kass, Vodanovich
  Callender, 2001)

Straussberger, S., Kallus, K.W. Schäfer, D.
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Introduction
What is a State of Monotony?

• ISO 10075 International Standards of Mental
  Workload
• Theory of Monotony Hansgeorg Bartenwerfer (e.g.,
  1960)

High repetition Low stimulation Extended
Time-on-task Low difficulty
Self-report
Physiological reaction
Behavior
MONOTONY AS STRAIN CONSEQUENCE
LOAD
STRAIN
Straussberger, S., Kallus, K.W. Schäfer, D.
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Introduction
Why Monotony in ATC?
Work conditions can be
uneventful
repetitive
Straussberger, S., Kallus, K.W. Schäfer, D.
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Introduction
Overall Research Motivation
How can monotony be operationalized? Which
contributing factors can be defined? Which
countermeasures can be introduced?
Straussberger, S., Kallus, K.W. Schäfer, D.
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Introduction
Research Questions Sim Approach
In simulated Air Traffic Control depending on
repetitiveness and dynamic density (DD) in
traffic is there a difference in performance
indicators subjective indicators
physiological indicators for a state of
monotony in Air Traffic Controllers?
Straussberger, S., Kallus, K.W. Schäfer, D.
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Methods
Experimental Design
2 (Break Activity) x 2 (Repetitiveness) x 2
(Sequence of DD) x 2 (Run) x 3 vs. 15
(Interval)-Mixed Design
Sample 24 Enroute ATCOs 18 male, 6 female
21-47 years (M29.5,SD6.0) Analysis ANOVA
rep. measures Level of Sig. a.05
DDSequence of Dynamic Density in Traffic (high
(h), low (l) )
Straussberger, S., Kallus, K.W. Schäfer, D.
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Methods
Operationalization of Repetitiveness Dynamic
Density
Straussberger, S., Kallus, K.W. Schäfer, D.
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Methods
Dependent Variables
Physiological Measures mean HR, mean HRV in
3-minute-intervals during scenarios,
Subjective Indicators during and after
scenarios During Scenario Thackray et al.,
1975 attentiveness, fatigue, boredom,
irritation, strain, concentration, motivation,
sleepiness NASA-TLX Mental demand, physical
demand, temporal demand, performance, effort,
frustration, overall workload feeling of
monotony, SA UWIST Mood Adjective List hedonic
tone, energetical and tense arousal Performance
Conflict resolution time, No. of STCA (Short
Term Conflict Alert) Other measures collected
e.g., initial state, recovery state, boredom
proneness,
Straussberger, S., Kallus, K.W. Schäfer, D.
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Results
Physiological level heart rate
Average corrected HR during first and second run
for groups with non repetitive (n12) and
repetitive (n12) traffic (Repetitiveness
F14.41, p.05 Run F1 17.68, p.001)
Straussberger, S., Kallus, K.W. Schäfer, D.
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Results
Physiological level HRV
Average HRV during first and second run for
groups with non repetitive (n12) and repetitive
(n12) traffic (Repetitiveness F17.52, p.013
Run F1 24.98, p.000)
Straussberger, S., Kallus, K.W. Schäfer, D.
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Results
Subjective state



Average ratings in a composed indicator of
attentiveness, concentration, sleepiness (inv.)
and fatigue (inv.) in first and second run
depending on repetitiveness (Repetitiveness
F19.80, p.005 Repetitiveness x Sequence of
DD x Run x Interval F1 4.03, p.033)
Straussberger, S., Kallus, K.W. Schäfer, D.
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Results
Conflict Resolution Time


Average conflict resolution time in first and
second run depending on repetitiveness and
sequence of DD (Repetitiveness x Sequence of DD
x Run F1 3.43, p.08() )
Straussberger, S., Kallus, K.W. Schäfer, D.
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Results
Feeling of Monotony




Average ratings for feeling of monotony after
first and second run as a function of
repetitiveness and sequence of DD (Run x
Repetitiveness x Sequence of DD F210.57,
p.004)
Straussberger, S., Kallus, K.W. Schäfer, D.
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The significant experimental results
repetitive
Straussberger, S., Kallus, K.W. Schäfer, D.
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Discussion
Discussion

• Supports theory of monotony a combination of
  feeling of monotony, sleepiness and HR is an
  ideal indicator
• Physiological deactivation in cardiovascular
  indicators but more complex self-reports
• Impairing AND facilitating (mental workload,
  strain) effects of repetitive conditions
• Dynamic Density affects perceived monotony and
  motivational component
• Confirms earlier reported results (Bartenwerfer,
  1960 Thackray, 1975)

Straussberger, S., Kallus, K.W. Schäfer, D.
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Discussion
Conclusions and Outlook

• Implications
• for the development of ATC concepts and work
  design (e.g., task analysis for repetitive
  elements multi-method approach in simulation
  set-ups
• for work organization (e.g. position assignment
  in ACC depending on expected traffic requires
  more sophisticated tools for supervisors)
• ATCO Selection (boredom proneness?)
• Field study in ACC in progress

Straussberger, S., Kallus, K.W. Schäfer, D.
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On the way to a model of monotony

• Physiological
• Heart rate
• SCL
• Blink rate
• Subjective experience
• Boredom
• Mood
• Sleepiness
• Tiredness
• Concentration
• Alertness
• Feeling of Monotony
• Behavioral
• Performance pattern
• Behavioral activities

SITUATION

• repetitive
• TASK
• uneventful

Action/ Occupation

• Long-term
• Health
• Satisfaction
• Skills

INDIVIDUAL
CAUSES
CONSEQUENCES
t
STATES
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Air Traffic Control
there is monotony.
For further information sonja.straussberger_at_euro
control.int
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(No Transcript)
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Monotony in ISO 10075
WORK ENVIRONMENT
Mental Stress
INDIVIDUAL
Mental Strain
Mental fatigue
Reduced vigilance
Mental satiation
Monotony
Activation
Warming-up
Impairing effects
Facilitating Effects
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Methods
Procedure

• min
• Welcome, Summary of Controller Handbook, open
  questions 10
• Preparation of physiological measures
  Questionnaires 40
• Training 40
• Baseline, Scales 5
• Run 1 45
• Baseline, Scales 30
• Run 2 45
• Baseline, Scales 30
• Break with vs. without activity 10
• Run 3 10
• Baseline, Scales 5
• Performance Tests 15
• Remove equipment 5
• Debriefing 10 Total Time 295
• Session Start 800 vs. 1400

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Methods
Independent Variables

• Repetitiveness (repetitive vs. non-repetitive
  conflict patterns)
• Sequence of Dynamic Density in Traffic (high (H)
  - low (L) vs. H - L)
• 2 Runs (1. Scenario vs. 2. Scenario)
• (Intervals during Scenarios)
• Activity in Rest Break

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Methods
Counteracting Variables

• Continuous Variables
• RSQ (Recovery-Stress-Questionnaire, Kallus, 1995)
• ACS-90 (Action Control Strategy, Kuhl, 1992)
• Boredom Proneness Scale (Farmer Sundberg, 1986)
• Morningness-Eveningness-Scale (Horne Ostberg,
  1976)
• Big Five Markers (Goldstein, 1992,1999)
• Control Variables
• Initial State (FAL), age, sex, nationality,
  mother tongue, ratings for working position,
  experience, actual worked sector, handedness,
  body weight, body height, vision, smoking, time,
  room temperature, movement, respiration

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Methods
Dynamic Density

• Laudemann et al. (1998)
• Traffic density (amount of AC)
• Traffic complexity
• Heading Change
• Speed Change
• ALTITUDE CHANGE
• Minimum Distance
• Predicted conflicts
• (Controller intent)
• Crossing points
• 3-minute-intervals

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Results
Rating sleepiness
Average change from baseline in perceived
sleepiness during first and second run for groups
with non repetitive (n12) and repetitive (n12)
traffic (Run F114.35, p.001 Interval
F217.80, p.000 Run x Sequence F18.44,
p.009 Run x Interval x Repetitiveness
F25.83, p.011)
Straussberger, S., Kallus, W. Schäfer, D.
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Results
Some more Results
1Complex Interactions
Straussberger, S., Kallus, W. Schaefer, D.
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The explanations
Boredom
Monotony
External environment
Not much going on, it is always the same, it is
boring
uneventful
Work environment
Fatigue
I am tired, sleepy
Low Vigilance
repetitive
Stress
Underload
Satiation
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The experimental approach
Confounding/Control Variables Individual/Non-Indiv
idual
External environment
uneventful
Subjective Ratings cognitive/emotional/ motivatio
nal/strain mental workload mood critical
states
Work environment
Performance Conflict resolution time Short Term
Conflict alerts After Task Performance
Physiological indicators EEG, ECG, EDA, EOG
repetitive

• 2 x 2 x 2 x 3/15 - Mixed Design
• Repetitiveness (BS)
• Sequence of Dynamic Density (BS)
• Run (WS)
• Interval during Run (WS)

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The confusion
Monotony is the stimulus situation as
experienced by individual specific consequence
of work situations when continuous engagement in
a task of a restrictive nature is
required stimuli remain unchanged or change
only in a repetitive way
Boredom a negative dissatisfying emotional
state a psychophysiological state after
prolonged exposure to monotonous stimulation a
state including a cognitive, affective and
physiological component
Low Vigilance is the impaired state of the
intense readiness to respond to excitation the
impaired state of high-grade physiological
efficiency
Underload task demands too rare (quantitative
) or frequent but uniform without sufficient
engagement (qualitative)
Satiation a state of increased tension,
irritation and agitation in reaction to
repetitive tasks
Fatigue is a reversible state characterized by
the impairments of mental and physical functional
efficiency
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Monotony and similar critical states

repetitive/uneventful
Task

Controller State
task-related
motivational
energetical
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Monotony and similar critical states

repetitive/uneventful
Task

Controller State
task-related
motivational
energetical
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Methods
eDEP simulation environment
Straussberger, S., Kallus, W. Schäfer, D.