Intro to HuFactors/Ergonomics

Question 1

What is the worst-case outcome of bad design? What is the best-case outcome of good design?

Answer 1

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Question 2

revenge effects

Answer 2

ironic unintended consequences of mechanical, chemical, biological, or medical systems–not a side effect or a trade-off (Tenner, 1996)e.g., _________ hands cannot open child-proof bottles of pain relieversolution: “easy-open” bottles- side effect: cancer chemotherapy causing baldness(revenge effect: cancer chemotherapy causing another cancer)- trade-off: legally required safety features cause increase in airline fares(revenge effect: higher fares on safer airlines cause people instead to _____–which is more dangerous)

Question 3

what’s special about TiVo?

Answer 3

TiVo has won awards for design, including the remote control.users have strong emotional identification with TiVo (40% of users would rather give up their cell phone than their TiVo!)on-screen graphical user interface (GUI) used in conjunction with audio to providefeedback on successful or unsuccessful actions- can record TV shows based on user’s implicit preferencesREMOTE (gud feedback)-peanut shape is comfortable to hold for long periods• batteries placed in location that helps balance weight of the device• designed to have fewest possible buttons (originally 30, now 34)• labeled with understandable descriptions• green thumbs-up/red thumbs-down buttons used to “train” TiVo aboutyour likes and dislikes• buttons are coloured to give visual contrast; avoided bright/toylikecolours in favour of warmer shades• buttons vary in size and shape, and are made of pliable rubber• buttons give a “snap” feeling when pushed• buttons spaced far apart to avoid incorrect presses• engineers reduced time lapse between button-press and seeing results onscreen

Question 4

human factors psychology

Answer 4

“design & evaluation of equipment and systems people use, intentionally taking intoaccount how people operate”-uses scientific knowledge about human behaviorin specifying the design and use of a human-machine system.-Human factors discovers and applies information about human behaviors, abilities,limitations, and other characteristics to the design of tools, machines, systems, tasks, jobs, and environment for productive, safe, comfortable and effective human use

Question 5

Frederick W Taylor

Answer 5

-wrote Principles of Scientific Management- Scientific methods used in work (instead of “rules of thumb”) - believed there was “one best way” to do any job-workers selected, trained, and developed scientifically (not on their own) - management & workers cooperate to implement scientific procedures- management & workers do work for which they are best fitted-Bethlehem Steel, optimized shovel use for each task (diff materials)-cut workforce to 140 from 400-600 full timersalso studied incentives; used stopwatches for “time and motion study,” later banned until 1949 in US

Question 6

Frank Bunker Gilbreth (& Lillian Gilbreth) (1909)

Answer 6

associates of Taylor- studied bricklaying:bend over, pick up brick, look for best side, scoop up and apply mortar, place brick - designed scaffolding to reduce reaching distance; mortar scooped with other hand- number of motions decreased from 18 to 4.5- output increased from 120 to 350 bricks/hour (no layoffs!)-10 children, cheaper by the dozen

Question 7

Elton Mayo (c. 1924-1933)

Answer 7

-studied people working in experimental settings-studied 6 women, changed bunch of stuff, no rl to increase in productivity, so…-hawthorne effect: increase in productivity due to knowledge that one is being observed, confounded with environmental manipulations-maybe also due to friendly researcher rather than authoritarian boss, concerns heard, belong to team, novelty effects-studies not replicable really, poorly controlled (all changes made on monday morning_

Question 8

technological developments in WW2

Answer 8

• more complex weapon & transport systems developed - crashes typically blamed on “pilot error” (always stressed, little sleep, etc!)e.g., pilots of B-17 Flying Fortress retracted landing gear instead of controlling flaps during landing! - problems using equipment showed the need for human factors analysesChapanis (1999):- in 1943, modified B-17 controls:• attached wedge-shaped end to flap control• added small rubberized disc to landing gear control- shapes easily distinguished; map well to function- intuitive relationship between control shape and function (“shape coding”) - result: “pilot error” disappeared- inexpensive, simple design change,  huge impact

Question 9

Human Factors Professional Assoc

Answer 9

Institute of Ergonomics & Human Factors- formed in 1949 in ? as Ergonomic Research Society - changed name to The Ergonomics Society in 1977- changed name again in 2009- has about 1,200 members- UK basedAssociation of Canadian Ergonomists- formed in 1968 as Human Factors Association of Canada - changed name in 1999- has about 600 membersAmerican Psychological Association Division 21: Applied Experimental & Engineering Psychology- founded in 1957- has about 300 membersHuman Factors and Ergonomics Society- founded in 1957 as Human Factors Society of America - changed name in 1992- has over 5,000 members: BIGGEST

Question 10

Human Factors Training division

Answer 10

36% psychology (most)2% industrial design42% overall have PhDsmost work in industry (computer/software)followed by business and govt, then academia

Question 11

Common work of Human Factors peeps

Answer 11

write reports (most common item)• make formal briefings/presentations• determine system requirements; write system goals and objectives • develop experiments to test theories or systems• verify system designs meet human factors standards• schedule project activities/manage others

Question 12

Certification

Answer 12

requires professionals to meet standards of Training and Experience - rationale:• protects users of HF/E services• protects the reputation of the field • improves quality of practice-highest designations require master’s degree, 3 years of experience, and a written exam-“associate” levels exist for those who are in training

Question 13

Five fallacies assumed by designers

Answer 13

1. This design is satisfactory for me, so it’ll be satisfactory for everyone else. (designer has perfect knowledge of his own system…)2. This design is satisfactory for the average user, so it’ll be satisfactory for everyone else. 3. The variability of human beings is so great that it cannot possibly be catered for in anydesign, but people are so adaptable it doesn’t matter anyway.4. Ergonomics is expensive and because products are purchased on appearance andstyling, ergonomic considerations may conveniently be ignored.5. Ergonomics is an excellent idea. I always design things with ergonomics in mind, but Ido it intuitively and rely on my common sense, so I don’t need any data. STAHP. NO, BASED ON SCIENCE OK

Question 14

Benefits of human factors

Answer 14

• increased product sales (More usable by more people… Increases sales!)• increased user satisfaction• increased user productivity• decreased customer support costs • decreased development costs• decreased employee turnover/sick leave • decreased training costs• decreased maintenance costs

Question 15

General Systems Theory

Answer 15

developed by Ludwig von Bertalanffy (1968), Hungarian biologist educated in Vienna- reacted against reductionism; wanted to unify the sciences (what about the big picture? the whole organism? not just it’s parts, BIOLOGY :( )- emphasized that real systems are open to, and interact with, their environments- focused on arrangement of and relations between the parts which form a whole- the same concepts and principles of organization underlie different disciplines, providinga basis for their unification (scientists starting to only know more and more about less and less, too much depth not breadth)• in WWII, worked on gunfire control, the problem of pointing a gun to fire at amoving target• invented CYBERNETICS: a theory of the communication and control of regulatoryfeedback

Question 16

Systems Engineering

Answer 16

• interdisciplinary approach to:• requirements• design, development, production, and operation • coordination of teams (diff teams work on diff tasks, must be coordinated)• automatic control of machinery- aids in management of complex projects in specialized domains e.g., logistics (can we automate project development? similarities across projects)- holistic in nature: requires consideration of all system components, everything that interacts with the system, as well as the environment in which the system operates

Question 17

how apply the systems approach

Answer 17

• examine components that could contribute to systems failure - from the micro level…• equipment design – change design of tools• environmental design – change features of the work environment such astemperature, lighting, sound - …to macroergonomics• task design – change how task is accomplished• training – change worker behaviour by providing skills and teaching procedures • selection – recognize individual differences in ability to accomplish work

Question 18

Systems Failure Example: 2003 Blackout

Answer 18

-electric power system• generation : power plants generate electricity• transmission: high-voltage lines carry electricity• distribution: substations, transformers “step down” power for customers- these components are owned and run by energy companies and utilities- oversight handled by non-profit Independent System Operators (ISOs), that coordinate,control, and monitor transmission systems- power “grid”:• network of transmission lines and switching stations (East, West, Texas… lol)• North America has three distinct grids or “interconnections”: allow sharing ofgeneration reserves, mutual help in dealing with disturbances- biggest blackout in US history: 50 million people in eight states and Canada blacked out - 264 power plants shut down; 62 GW of power lost- some areas without power for up to 4 days- total cost: US$8 billion

Question 19

Causes of 2003 Blackout

Answer 19

• causes:• inadequate system understanding- FE: insufficient planning to know Cleveland-Akron area was deficient in power supply (kept having to import power)• inadequate situational awareness- alarms, computers malfunctioned; poor communication; insufficient backups• inadequate tree trimming- poor maintenance (one tree was over 42’ tall)- lines sag with heat/low winds, and higher current• inadequate diagnostic support- MISO had inadequate monitoring systems, so could not identify problems - critical computer malfunctioned; was shut off as technician went for lunch- interacting factors at multiple levels: hot weather (environment) × high demand (individual) × poor vegetation control (supervision) × software failure (infrastructure) × poor communication (interpersonal) × mismanagement (management) × interconnected electrical grid (infrastructure) × poor oversight (legislation) (this is a simplification!)

Question 20

The TIpping Point

Answer 20

• term coined by sociologist Morton Grodzins (1958), referring to “white flight” from neighbourhoods post-WWII as Black families moved in(After WW2, influx of African Americans to white neighbourhoods, immigrants. Then white people would flight from neighbourhoods… What is that tipping point that makes them all leave?)- uses metaphor of an epidemic (nonlinear systems/geometric progression): little things can have a big effect (and vice-versa)- also: many factors may contribute to a result, but not in equal proportions- popularized by Malcolm Gladwell’s (2000) book, The tipping point: How little things canmake a big differenceZIMBARDO- parked 1959 Oldsmobile on a street in Palo Alto near Stanford: sat untouched for a week - identical car parked in the Bronx near NYU, but licence plates removed and hood up: wasstripped within a day- then smashed Palo Alto car with a sledgehammer: people vandalized car until it waswrecked- led to “broken windows” theory

Question 21

Broken Windows Theory

Answer 21

• fix small things like repairing broken windows, removing graffiti, or cleaning litter - this leads to two outcomes:1. vandalism and petty crime will be deterred2. major crime will be prevented- thus, respectable citizens will not move away, averting a vicious circle of increasingantisocial behavioure.g., Keizer & colleagues (2008):- attached flyers from fictional sportswear shop to handlebars of bicycles• control: 33% threw flyers on the ground• put graffiti on nearby wall: 69% littered- envelope with visible €5 note inside was sticking out of a mailbox• control: 13% of passersby stole envelope• graffiti on mailbox/litter on ground: 25% stole envelope- conclusion: behaviour is governed by social norms- problems arise when perception of what is common (e.g., graffiti) does not matchexpectations of society (e.g., no graffiti sign)(small things, that make something look like it isn’t being taken cared of, results in disproportionate treatment subsequent)

Question 22

pros cons of broken window theory

Answer 22

pros & cons:-environment is a likely contributing determinant of behavioure.g., Crime Prevention Through Environmental Design (CPTED) (initiative in edmonton to reduce crime through environmental design)-some evidence: credited with drop in crime in NYC in the 1990se.g., Rudolph Giuliani’s “Quality of Life” campaign in New York focused on seemingly trivial fixes such as removing graffiti, clearing signs of vandalism, and sweeping the streets-many other factors contribute to criminal behaviour e.g., innovative policing, demographic changes, etc.-evidence is equivocal/confoundede.g., evaluation of “disorder” more dependent on race and socioeconomicstatus (diff people have diff definitions of disorder)

Question 23

common themes throughout course

Answer 23

-systems approach—every event has determinants at multiple levelse.g., physical ergonomics to individual and group behaviours to organizations and laws-error, impossible to avoid!—tombstone technology, human deaths lead to improvements in tech to prevent further death-design, structure vs function-consider the user perspective, not just designer-trade-offs impossible to avoid(e.g. cost vs safety), balance these-feedback is critical in design! for refining performance