Physical Ergonomics & Human-Computer Interaction Flashcards
anthropometryppl are not all the…poor design for mechanical abilities can lead to…e.g.?
measurement of human body and its biomechanical characteristics (mechanical capabilities of human skeleto-muscular systems)- people are not all the same size:design system to fit only one person > few others would be able to use it- poor design for mechanical abilities of the human body can lead to discomfort or injury!e.g., repetitive strain injuries: RSIspoor computer keyboard  Carpal Tunnel syndrome: inflammation and swellingin the tendons that run through the narrow carpal tunnel in the wrist
static measures?dynamic measures?
static measures- passive dimensions of human body- used to determine size/spacing requirements of workspacee.g., height, weight, seat-to-elbow height-averages of these have been published as common bldg standards!dynamic measures- dynamic, changing properties of human bodye.g., strength, endurance- used to match dynamic characteristics of controls to usere.g., strength of fingers, force of leg pushes, range of motion for various joints-changing strength/endurance over a day (lifting tire at begin of shift very diff from end of shift!!!)
clothing standardsdeveloped by? from?based on who? representative?-testing?what is vanity sizing?
- developed by U.S. Department of Commerce- currently used database for women’s sizes 2-20 based on a 1941anthropometric study of women in military!- not representative–biased towards young, unmarried white women - testing of fit is rare; model may be hired- vanity sizing: nominal size has become larger over time (2 becomes 0!)
problems w/ anthropometric data
-use measurements from intended population, BUT-differences b/t….ethnicities (asian vs north american).5th percentile torso length & 5th percentile head height =/= 5th percentile stature!! (no such thing as someone who is avg in every regard).age differences (shrink as grow older).sex differences.effects of clothing (where put your coat at stadium? on chair!).changes over time due to diet/habit, changes in size/fitness of population! (height & weight incr. over years!).e.g. newer stadium seats are 5cm wider
solutions to variability in anthropometric data
design options- one size fits all- make several sizes- standard: design to fit 5th to 95th percentile of population- make design adjustable!:• best if adjustment only needs to be done once• user may not make difficult/frequent adjustments incorporate dynamic measures • test the design!
aeron chair: basicsconsidered?
-made by research/design firm Herman Miller since 1994-has won numerous design awards-widely considered v. comfortable, extermely adjustable, highly aesthetic (in museums)
aeron chair: structuremade of?seat and back made from?front edge?tilt?sizes?customization?
• made mostly of recycled materials• seat and back made from “Pellicle®” (thin skin or membrane): synthetic, flexible mesh• “waterfall” front edge reduces pressure on thighs, increases circulation• Kinemat® tilt allows forward tilt-to-backward recline• comes in three different sizes• can be customized with different modules, including armrests, bases, andPostureFitTM kit (gives custom-fitted support to the sacrum: base of the backwhere the spine meets the pelvis)
aeron chair: design processconducted?pellicle?design evaluated by?field studies?tested with?
conducted anthropometric studies (measuring popliteal height, forearm length, etc.)• did pressure mapping and thermal testing of Pellicle® (can get pressure sores from sitting chair w/ pressure on same points. research to distribute weight evenly)• design evaluated by ergonomists, orthopedic specialists, and physical therapists• performed field studies with representative sample of 224 people (GIANT, determined chairsize preference is most strongly related to height and weight) • tested with end users (rigorous testing!)
aeron chair: criticisms?price?difficulty?chair contact?softness?
-expensive: around 1k!!!-difficult to adjust-atypical contact of chair on back (sacrum)-pellicle soft, but foam cushion/edges of chair fricking hard
universal design (aka?): definition?rationale?
aka inclusive design-“the design of products and environments to be usable by all people, to the greatest extentpossible, without the need for adaptation or specialized design”rationale-54m in US had some level of disability, 26m severe-prompted by legislation in aust, canada, uk, USA
universal design: 7 principles/guidelines
- equitable use2. flexibility in use3. Simple & intuitive use4. Perceptible information5. Tolerance for error6. Low physical effort7. Size and space for approach and use
universal design: 1. equitable useaka?a) b) c) d)?
aka can be used by people having diverse abilitiesa) provide the same means of use for all users e.g., automagic doors (works same for everyone)b) avoid segregating or stigmatizing any users e.g., diaper-changing station in Men’s roomc) ensure privacy, security, and safety equally to all users e.g., TDD (deaf) 911 serviced) make the design appealinge.g., OXO Good GripsTM (not just for ppl with arthritis)
universal design: 2. flexibility in useaka?a,b,c,d
aka accommodates a range of individual preferences and abilitiesa) provide choice in methods of usee.g., ramp or stairsb) accommodate right- or left-handed usee.g., ambidextrous scissors c) facilitate user’s accuracye.g., big-button keys (for prof’s dad w/ diabetes and losing sensation in fingers)d) provide adaptability to user’s pacee.g., speed control on answering machine (slows pace of message so can record number at end of it!!!)
universal design: 3. Simple & intuitive useaka?a,b,c,d,e
aka easy to understand, despite user’s experience, knowledge, language skills, or concentration levela) eliminate unnecessary complexitye.g., single-lever faucetb) be consistent with user expectationse.g., Mercedes-Benz seat control (natural mapping)c) accommodate a wide range of literacy and language skillse.g., IKEA® assembly instructions: drawings only!!d) arrange info consistent with its importancee.g., instructions on inside of washer lide) provide effective prompting and feedback during and after taske.g., computer displays operation progress (don’t be at 100% and not actually done loading!!!)
universal design: 4. Perceptible informationaka?a,b,c,d
aka necessary info is communicated to the user, regardless of ambient conditions or sensory abilitiesa) use multiple modalities (pictorial, verbal, tactile) for redundant presentation ofessential infoe.g., visual/auditory/tactile thermostat b) maximize “legibility” of essential infoe.g., contrast between lids and bowls (diff colors, tupperware!)c) differentiate elements in descriptive ways (i.e., make it easy to give instructions)e.g., audio plugs/jacks have different coloursd) make devices compatible for people with sensory limitationse.g., closed captioning (descriptive audio, pay to hear what’s happening on screen!)
universal design: 5. Tolerance for erroraka?a,b,c,d
aka minimizes hazards and adverse consequences of accidental/unintended actionsa) minimize hazards and errorse.g., Bagel Guillotine® (cutting bagel while holding in hands agh!)b) warning of hazards/errorse.g., Mr. Yuk (if mr. yuk is on it, don’t touch it!!!)c) provide fail safese.g., “undo” software function, auto backupsd) discourage unconscious action in tasks requiring vigilancee.g., “deadman” handle on lawnmower
universal design: 6. Low physical effortaka?a,b,c,d
aka can be used efficiently and comfortably with a minimum of fatiguea) allow user to maintain a neutral body positione.g., Microsoft® Natural Keyboard b) use reasonable operating forcese.g., lever handles on doors c) minimize repetitive actionse.g., speech recognitiond) minimize sustained physical efforte.g., Travelpro® Rollaboard® luggage
universal design: 7. Size and space for approach and useaka?a,b,c,d
aka user is not restricted by body size, posture, or mobilitya) provide clear line of sight to important elements for any user e.g., lowered counters (elderly or in wheelchair rite)b) make reaching to components comfortable for any usere.g., front-mounted controls on KitchenAid® range (otherwise reach across boiling water!)c) accommodate variations in hand and grip sizee.g., open-loop door hardware (just have to put arm or hand in loop)d) provide adequate space for the use of assistive devicese.g., wide gate at subway station (for people w/ wheelchairs)
