Situation Awareness: Requisite
for e-Navigation
Michael Hertz, PhD
Progeny System
[email protected]
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SA defined by discipline
Psychological Approach
Situation Awareness is
something that can only exist
in the minds of people. The
unit of analysis is the
individual and that team
situation awareness is a
summation of individual
situation awareness.
Engineering Approach
Systems Ergonomic Approach
Situation awareness is in Places emphasis on the interaction
the world, represented between people and their artifacts
in the world, to propose that
in the artifacts and
objects that people use. situation awareness functions like
distributed cognition. This means
The unit of analysis is
that the unit of analysis the whole
the things that people
socio-technical system.
interact with.
Our approach has been the Systems / Ergonomic Approach to
view humans as part of the system and to argue that
technology by itself will not fix SA errors
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Axiom #1: For it to be Real, it must be
Measureable
To be useful, the SA models must make
predictions on human / system performance
that can be tested and validated
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Situation Awareness, Cognitive Load
and Training
• The term cognitive load is used in cognitive psychology
to illustrate the load related to the executive control of
working memory
• Types of Cognitive Load
– Intrinsic
• All tasks take some cognitive processing, no matter how simple the
task is for the user. (influenced by training, experience, decision
support systems)
– Extraneous
• Impact to the cognitive processing created by manner of data
presentation
– Germane
• Aspect of cognitive load related to generating, processing and
automating schemas
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Cognitive Load: Visualized
But can it be measured?
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Traditional Cognitive Load Measures
Type of cognitive
load measure
Measure
Main Research Question
Subjective
Subject rating scales
Learner’s subjective assessment of task demands
Objective
Learning Outcomes
Relation between instructional design and knowledge
acquisition
Time-on-task
Learner’s investment in the learning process
Navigation behavior,
help seeking behavior
Learner’s information need
Task complexity
Relation among affordances instructional design and
knowledge acquisition
Secondary task
analysis
Mental load induced by the (primary) learning task
Eye-tracking analysis
Basic behavioral aspects of information processing and
their relation to learning outcomes
Efficiency measures
Optimizing instructional design decisions by calculating
the relation of invest effort and learning outcome
Combined
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Schemas / Training Impact
Experience the situation in a changing context
Relevant details
similar to previous
experience or
training?
Perceived as typical
Recognition has four byproducts
Expectations
Relevant
Cues
Plausible
Goals
Typical
Actions
Long
Term
Memory
Evaluate Action
Yes
Cognitive Load
Will it work
Modify
Yes, but
Implement Course of
Action
Remember Situation Details,
Course of Action and Evaluate
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Outcome
Potential Cost Savings : Training
• ~80% of the material
presented in training courses
are forgotten before the
Mariner has the chance to use
it.
“Forgetting Curve”
– The 20% that is retained will be
different for each individual
– A sizable portion of the mariners
will retain even less than 20%
By monitoring cognitive load and then varying
the difficulty of the training, significant
improvements in retention are possible
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Potential Cost Savings:
Human Factors Design
• User Human-Machine design and
development is hard to measure objectively
– Objective psychophysiological measurements can
provide an objective, quantitative measure of
Cognitive load
• Allows for comparisons of two user interfaces on their
associated impact to the end user”
– Quantifiably define “ease of use”
Metrics can be developed to compare the impact of
different navigational aids or user interface designs
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Potential Cost Savings :
Error Avoidance
• Cognitive Overload leads to
errors
– Objective measurement can
be used to predict when a
person will enter into a
cognitive overload state
• Performance degradation is
quick and significant
• After Overload event, there is
a delay in getting back to
satisfactory performance
Objective measurements could be done during job
execution, or in simulators. Research has shown
value in “metacognition” alone.
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Training Optimization
Optimal Cognitive Load
Normative Load
Under Load
Short Duration Between Dropping Cognitive Load
Values Highlights Training Material For After Action
Reviews, Or Longer Term Training
Significant Drop Also
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Provides Insight For Debriefs
Progeny’s Psychophysiological
Hardware
• Measures EEG, Galvanic Skin Response, and Heart Rate.
• Writes Data to remove database for post hoc analysis
• Wireless and operates in the 900MHz band
Example Data
Cognitive Overload
Event
Conclusion
• Objective measurement of Cognitive Load is
possible.
• Through the use of Cognitive Load
Measurements
– Increased retention of training
– Objective comparison of User Interfaces
– Objective measurement of the value of different
sailing aides
More work is needed to validate preliminary
findings, but results are promising
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Questions?
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•System Capability
•Interface Design
•Stress & Workload
•Complexity
•Automation
Situational Awareness Global
Assessment Technique Model
Task / System Factors
Feedback
Situational Awareness
State of the
Environment
Perception of
Elements in
Current Situation
Level 1
Comprehension
of Current
Situation
Level 2
•Goals & Objectives
•Preconceptions
(Expectations)
Projection of
Future State
Decision
Performance
Of Action
Level 3
Information Processing
Mechanisms
Long Term
Memory Stores
Automaticity
•Abilities
•Experience
•Training
Individual Factors
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Another SA Model
Environment
available
information
Modifies
Samples
Invariant
Knowledge
Directs
Action
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Methodologies compared for Cognitive Loading Measurement
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Existing Measures of SA
(not model based)
Knowledge- Based Measures of Situational Awareness
Strengths
• Isolates components of current situation
awareness
• Provides insight into development and
maintenance of situation awareness
Potential Limitations
• Can no necessarily be used to predict
final performance of operator
• Easier to measure declarative knowledge
than procedural knowledge
• Possibly intrusive into operator’s task
Verbalization Measures of Situation Awareness
Strengths
• Provide insight into both situation
awareness and thought process
• Provides insight into perceived
importance of information
Potential Limitations
• Can no necessarily be used to predict
final performance of operator
• Easier to measure declarative knowledge
than procedural knowledge
• Limited by user’s ability to relate all
considerations during experiment runs
• Possibly distracting
Performance-Based Measure of Situation Awareness
Strengths
• Assess final performance of system and
records operator’ actions
• Sufficiency of situation awareness can be
inferred in some situations
Potential Limitations
• Not a direct measurement of operator’s
situation awareness
• Easier to measure procedural knowledge
than declarative knowledge
• Limited by descriptiveness of available
performance measures
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System View
SIM /
STIM
N-back
Training Event
Tactical System
Nuclear Power
Equipment Operation
Person
Psychophysiological
measurement
Analysis
Desktop
Web-app
Mobile
Body Contact:
No Body Contact:
EEG
EEG
GSR
Pulse
Pulse
Breathing
Breathing
Posture
Posture
Eye
Eye
Keyboard / mouse
Performance Model
Data Network
Domain Specific:
Sailor
Harbor Pilots
Air Traffic Control
Commercial Drivers
WiFi
PSC-WSN
Bluetooth
Cell / Radio
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