Engineering Psychology PSY 378F

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Engineering PsychologyPSY 378F

• University of Toronto
• Fall 2002
• Lecture Times and Location W 6-9 PM SS 1086
• Instructor Justin Hollands, Defence RD Canada

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Course Overview

• Who am I, who are you?
• Background, objectives
• Syllabus
• Text
• Keeping up with reading
• Grading
• Late assignments and missing exams
• No extensions

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Lecture Overview

• What is Engineering Psych?
• Relation to HF
• Two Loops
• A Brief History of Eng Psych
• Bad Design/Good Design

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Definition of Engineering Psychology

• Whats Engineering Psychology?
• Not psychoanalyzing engineers or manufacturing
  psychologists
•  Eng psych is applying psychological concepts to
  design of human-machine systems

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Relation to Human Factors (HF)

• How does engineering psych relate to HF?
• What is HF?
• Designing machines that accommodate the limits of
  the human
• Emphasis on DESIGN

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Role of Theory

• Although eng psych. is applied, intent is to go
  beyond specific, one-time application
• Long-term objective to provide a useful theory of
  human performance
• How and Why people
• Buttons in Microsoft Word-better on top or
  bottom?
•  This is a HF question

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Role of Theory (contd)

• Why is top (or bottom) better? is an Eng.
  Psych. question.
• Trying to develop theory
• It is our firm belief that a solid grasp of
  theory will provide a strong base from which the
  specific principles of good HF can be more
  readily derived. (Wickens Hollands, 2000)

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HF vs. Experimental Psych

• Goal of HF
• To apply knowledge in designing systems that
  work, accommodating human limits, and exploiting
  the advantages of a human operator as well
• Goal of Experimental Psychology
• to uncover the laws of behavior thru experiments.
• Experimental design unconstrained by any
  requirement for application

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Intersection

• Engineering psychology is intersection of human
  factors and experimental psychology

HF
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HF, not Eng Psych

• There are areas of HF that are not Eng Psych
• Physical ergonomics
• Work physiology
• Manual-materials handling
• Anthropometry
• Environment Illumination, atmospheric
  conditions, noise, motion
• Issues of muscle fatigue, whether someone can fit
  in a cockpit, how bright the work environment is
• Concern physical properties of workers body, not
  brains information processing capabilities
• These are all HF concerns, but are not Eng Psych

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International Differences

•  In US, HF related to physical properties of
  interface or work environment is called
  ergonomics (left part of leftmost Venn circle
  might be labeled ergonomics)
•  In Europe, ergonomics means same thing as HF
  (entire HF circle on left might be labeled as
  ergonomics)
• So terms have different shades of meaning

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Association of Canadian Ergonomists

• ACE is Canadian national society for ergonomics
• Has membership of around 700 people
• Was renamed in mid-90s
• Previous name Human Factors Association of
  Canada
• Why? People didnt know what human factors was
• Ergonomics has become a more recognizable term to
  people outside the discipline, more so than human
  factors

http//www.ace.ergonomist.ca/
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• HFES US national society www.hfes.org
• Has membership of around 5000 people
• HFS renamed HFES in mid-90s
• Why? people didnt know what human factors was
• The last straw was an article from Computerworld,
  May 1991, which stated that
• There is no professional ergonomists
  association and there are only about 300
  professional ergonomists in the entire US

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Engineering Psychology not a Profession

• There is no professional association of
  engineering psychology
• Anyone who calls themselves an engineering
  psychologist is probably a member of HFES or ACE
• Engineering psychology and HF are therefore very
  tightly linked
• Eng psych more like an academic discipline

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Summary

• Eng psych differs from HF (or ergo,whatever you
  want to call it) in two ways
• more theoretical
• more psychological

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Two Loops

• Two loops important for Eng Psych
• One is model of human-machine system
• Other is design cycle

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First Loop Human-Machine System
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Psychologists Engineers Domains?
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Human-Machine System Psych View
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Second Loop Design Cycle
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Second Loop Design Cycle
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A Brief History of Engineering Psychology

• Early HF work (ca 1900-20s)
• Taylor task analysis, time and motion studies
• workers movements are analyzed across time to
  determine best way to perform a task.
• Nurse-scalpel hospital surgical teams--prior to
  work by Gilbreths, surgeons picked up their own
  instruments from tray.

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A Brief History of Engineering Psychology (contd)

• Eng. Psych got its start during WWII
• During war it became clear that even with the
  best selection and training, operation of complex
  equipment still exceeded peoples capabilities
• Mechanically-sound planes were crashing into the
  ground--they were too hard to fly
• So experimental psych. were enlisted to
  collaborate with engineers to design various
  military equipment, e.g., aircraft cockpits,
  radar consoles, binoculars, training devices

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A Brief History of Engineering Psychology (contd)

• Some details of WWII era HF can be found in The
  Chapanis Chronicles, by Alphonse Chapanis (1999),
  Aegean Press

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A Brief History of Engineering Psychology (contd)

• Second motivation came from evolutionary trends
  in technology
• Functions previously allocated to the human could
  be performed by machines

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Work Has Changed

• Workers task changed from doing to
  monitoring or supervision
• less physical, more psychological

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Split Second Delay

• Big changes in speed and complexity of tasks too
• Split second delay means nothing for an oxcart,
  but everything--life and death--for fighter pilot

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Post WWII

• 1945-1960

• Engineering psychology laboratories established
  (USAF and US Navy)

• Also in the UK (MRC and DSIR)

• Human factors group at Bell Labs (1948)

• Ergonomics Society formed in UK (1949)

• Chapanis, Garner, and Morgan (1949) Applied
  Experimental Psychology Human Factors in
  Engineering Design

• Ergonomics first volume (1957)

• Human Factors first volume (1958)

• APA Division 21, Engineering Psychology (1958)

• International Ergonomics Association (1959)

• 1960-1980

• Human factors started to appear outside military
  and space applications

• Rapid developments in computing spawned new
  disciplines (HCI) and societies

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Last 2 Decades

• 1980-1990

• Widespread computer availability brings human
  factors to the fore

• New software, often unfriendly (Unix, MS-DOS,
  etc)

• Computer hardware prompts new attention to
  ergonomics

• Three Mile Island (actually 1979) narrow escape
  from meltdown

• Bhopal, Union Carbide (1984) 4000 dead 200,000
  injured

• Chernobyl (1986) 300 dead ???????? injured
  massive property damage

• Litigation forensic issues 15 HFS members act
  as expert witnessses

• 1990 and beyond ...

• Computing (in all areas) health (medical
  devices, facilities for elderly) will drive
  demand for engineering psychology specialists

• NRC (USA, 1991) projected demand for HF
  specialists will exceed supply

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Bad Design and Good Design

• Not just aviation, military domains affected
• Bad product design can affect all of us
• Phasors on Stun (Casey, 1998)
• e.g., Search of the Lost Cord, p. 177
• Whos at fault?

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• 9 pin connector for external serial port
  connections

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10 lead ekg patient cable
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Bad Design and Good Design

• IKEA bookshelves--wooden pegs

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Bad Design and Good Design

• Refrigerator example
• control panel suggests that the two controls are
  independent--when in fact they are not

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Bad Design and Good Design

• Refrigerator example
• control panel suggests that the two controls are
  independent--when in fact they are not

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Bad Design and Good Design

• Refrigerator example
• control panel suggests that the two controls are
  independent--when in fact they are not

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Principles

• Principles for good design (Norman,1988)
• 1) Provide a good conceptual model
• 2) make things visible
• 3) provide a mapping
• 4) provide feedback

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Principle 1 Provide a good conceptual model

• Allows us to predict effects of our actions
• Otherwise we guess
• We dont understand why our actions have certain
  effects
• Cant predict outcomes of other actions
• Dont know what to do if something goes wrong
• Fridge controls are good example of poor
  conceptual model

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Principle 2 Make Things Visible

• Compare a phone to a car
• Car
• 1 ctrl/function
• things are visible
• there are natural relationships between the
  controls and things being controlled--not
  arbitrary
• there is good feedback (e.g., rolling down a
  window vs. putting someone on hold)

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Principle 2 Make Things Visible (contd)

• Phone
• no visible structure
• mappings are arbitrary (81, pressing number
  keys)
• controls have multiple functions
• poor feedback
• Advantages of 1 ctrl/function
• Each control can be labeled
• Labels serve as reminders that the function is
  available
• Also serve as prompts--promote exploratory
  behavior

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Principle 3 Provide a Mapping

• Watch out for improper mappings (improper
  affordances)
• Norman--car radio
• Moving control left/right does not correspond to
  function to move sound from front to rear
  speakers
• Control does not even look like part of the
  radio--not grouped
• Maybe it affects the relative volume of the horn
  on the L/R side of car
• Good mapping -- car seat

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Principle 3 Provide a Mapping
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Principle 4 Provide Feedback

• No feedback after an action produces problems
• When deptal sec. put someone on hold, she said,
  as a matter of course, are you there?
• Small light to indicate hold would solve the
  problem
• Or better button to select line