Transcript Work Physiology - دانشگاه علوم پزشکی

Cognitive ergonomics
A.H. Mehrparvar, M.D.
Yazd University of Medical Sciences
Department of Occupational Medicine
Terminology
Engineering Psychology (psychologic
engineering)
 Human Performance Engineering
 Human Factors
 Ergonomics
 Cognitive Ergonomics
 Cognitive Engineering

Why Consider Human Factors?
Enhance efficiency (productivity)
 Ensure safety
 Assure tasks are within human
capability
 Improve human performance
 Gain market acceptance
 Reduce costs (economic, legal, social)

Human in the human factors

Humans are involved in all aspects of
technology



Designers
Users (operators)
Maintenance personnel
The successes (and problems) of
technology:
 machine failure
 human error
 interaction of humans and machines
(system error)

Human-Machine System
Environment
Human
Machine
Sensory
Motor
Interface
Cognitive
Display
Processor
Control
Matching Humans and Machines

I. “Fitting the Machine
to the Human”: Display,
control, and interface
design
Human
II. “Fitting the Human
to the Machine”:
Selection and training
Sensory
Cognitive
Motor
Display
Interface

Machine
Processor
Control
Examples of I: Display, Control and
Interface Design

Voice (auditory) vs. data link (visual)
for controller-pilot communications

Monitoring for excessive operator
workload or fatigue using
neuroergonomic measures
Examples of II: Selection and
Training
Selecting for high-performance skills
(e.g., pilot)
 Developing selection tests for new
occupations
 Training special populations (e.g., older
adults in ATM usage, or home
automation)

Engineering Psychology vs. Human Factors

The aim of engineering psychology:


not simply to compare two possible designs for
a piece of equipment [which is the role of
human factors]
but

to specify the capacities and limitations of the
human [generate an experimental data base]
from which the choice of a better design
should be directly deducible
Because Minds and Brains are “Situated”—in a Body
and Environment with Artifacts and Tools—
Hence Cognitive Engineering
Neuroergonomics
- Using Brain Function to Enhance Human Performance
in Complex Systems
- The scientific study of brain mechanisms and
psychological and physical functions of humans in
relation to technology, work, and environments
Definition
Cognitive Ergonomics
 Cognitive Engineering
 Psychological Engineering:
the scientific discipline that studies the
cognitive processes in the design of
technology and the environment in which
this technology is used by people

Cognitive ergonomics - definition
studies cognition in work settings, in order
to optimize human well-being and system
performance
 focuses on the fit between human
cognitive abilities and limitations and the
machine, task, environment

Examples
designing a software interface to be "easy
to use“
 designing a sign so that the majority of
people will understand and act in the
intended manner
 designing an airplane cockpit or nuclear
power plant control system so that the
operators will not make catastrophic
errors

Cognitive ergonomics (cont.)
Cognitive ergonomics studies cognition
in work settings
 in order to optimize human well-being and
system performance

an emerging branch of ergonomics that
places particular emphasis on the analysis
of cognitive processes
 Cognitive processes:




Diagnosis
Decision making
planning
Cognitive ergonomics aim to enhance
performance of cognitive tasks by:
 user-centered design of human-machine
interaction and human-computer
interaction
 design of information technology systems
that support cognitive tasks
 development of training programs
 work redesign to manage cognitive
workload and increase human reliability

examples- narrow definition
TV or DVD player remote control — button
placement, orientation, size, shape,
texture, and color
 Computer software menu — the number,
color, arrangement, modes of access, and
hierarchical nesting of the screens in an
online help system
 Design and layout for the buttons, knobs,
and dials on a car stereo
 Warning labels on consumer products —
color, configuration, size, and placement

Examples- broad definition
The configuration of equipment and
furniture in a hospital operating room to
maximize team performance and minimize
errors of perception, attention and
judgment
 The design of a commercial jet’s cockpit to
correspond to the crew’s natural
tendencies in perception, memory, and
decision making

The creation of an office environment to
minimize distractions and maximize
productivity and performance
 The arrangement of a classroom to
maximize information exchange,
knowledge creation, and acquisition

Recent models of cognitive ergonomics
involve three dimensions:
 Usefulness
 usability
 acceptance

What is “Usability”?
The degree to which a product or service
is easy to use, easy to learn, and
optimized for efficiency
 ISO 9241-11 “Guidance on Usability”
 Extent to which a product can be used by
specified users to achieve specified goals
with effectiveness, efficiency and
satisfaction

Effectiveness - Accuracy and
completeness with which users achieve
specified goals
 Efficiency - Resources expanded in
relation to the accuracy and completeness
with which users achieve goals
 Satisfaction - Freedom from discomfort,
and positive attitudes towards the user of
the product

Related fields
 Human-computer interaction
 Neuroergonomics
 Supervisory control

Physical ergonomics Vs. cognitive
ergonomics
physical ergonomics focuses on our bodies
 Cognitive ergonomics is interested in what
goes on in our brains:
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the way our senses perceive information
the way in which we understand and interpret
it
what determines the decisions we make
Objectives of cognitive ergonomics
shorten the time to accomplish tasks
 reduce the number of mistakes made
 reduce learning time
 improve people’s satisfaction with a
system

Cognition is the processing of
environmental information acting on the
environment
 any available system that processes
information in its environment to act upon
it could be called “Cognitive System” and
performs “cognitive work”.

ACTIVITITES OF THE COGNITIVE
SYSTEM

•
•
PERCEPTION:
complex sensory processes
primary images containing all information about the
concrete features of objects (visual, acoustic,
kinesthetic, olfactory, gustatory)

MEMORY:
•
ability to remember, recognize and recall
•
information is encoded, stored and retrieved.
•
active: structuring, constructive and creative psychic
mechanism.
•
THOUGHT: the process of information processing in
working memory

the analysis of cognitive tasks should
examine both the interaction of users with
their work setting and the user interaction
with artifacts or tools
Interaction:
 Collaboration to perform a task, to do
Cognitive Work
 For example, when describing the task of
driving a car we would say that: “My goal
is not to sit in my car and play with the
equipment. My goal is to sit in my car, so
that together we get from one point to
another in space, as safely and quickly as
possible”. This collaboration is
implemented through the interface.

Cognitive analysis of interaction
The allocation of functions to both humans
and artefacts
 The design of the interface through which
humans and artefacts communicate while
collaborating in performing the task

Human and artefacts interact to perform a
task by performing cognitive functions
 Therefore, the design of interaction is to
describe how these cognitive functions are
allocated to humans and artefacts
 “Adaptive function allocation” to mean
that functions could be re-allocated
through the interaction

Levels of functional analysis

the first cognitive level: sensory-motor

interaction is described from the point of view
of the characteristics of the human sensory
and motor systems
Interaction occurs when the output of the
device, be this visual, auditory, or of any
other physical type, is captured by human
sensory receivers
 human behaviour would be processed
through the motor system, and it is
essential that the device has the
necessary input systems to receive it in

Design phase
 Cognitive ergonomics is promoting "usercentered design", in the sense that users
are integrated in the design process as
early as possible
 “ User centred design addresses early and
continuous focus on users, empirical
measurements, iteractive design and
multidisciplinary design teams

Evaluation phase
 User centered design involves iterative
design, so that evaluation is conducted at
every stages of development. Most
evaluation methods aims at evaluating
usability and thus are described under the
usability article

Models in cognitive ergonomics
-
model of changeability
-
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Individual knowledge
Strategies
Cognitive styles
Personality factors
conceptual models of systems and of interaction
task models
Human-System Interface Technology
Human-Machine: Hardware Ergonomics
Human-Environment: Environmental
Ergonomics
Human-Software: Cognitive Ergonomics
Human-Job: Work Design Ergonomics
Human-Work System: Macroergonomics