ISyE/PSYCH 349 Exam 1 Review PDF

ISyE/PSYCH 349 Spring 2025 Exam 1 Basic Information Wednesday 2/19 in class 2:30p – 3:45p Format 25 multiple choice questions, 2 points each, 50 total points Canvas Exam (please bring your computer you used for the practice quiz!) We will be using Honor lock Covers: Intro...

ISyE/PSYCH 349 Spring 2025 Exam 1 Basic Information Wednesday 2/19 in class 2:30p – 3:45p Format 25 multiple choice questions, 2 points each, 50 total points Canvas Exam (please bring your computer you used for the practice quiz!) We will be using Honor lock Covers: Intro to HFE Design & Systems Thinking Evaluation Visual Perception Auditory Perception Other Perception Honor Lock Honor lock features enabled: Picture & room scan beforehand Screen recording Web traffic recording Browser guard Disable copy/paste Disable printing/screenshot The system will flag anything it finds ‘suspicious’ Honor lock does have chat support if there are problems as you are taking the exam (not anticipated, especially if you complete the practice quiz first!) I have paper copies only for those who requested it ahead of time I also bring a few backup paper copies just in case, but usually only about 10 Practice Quiz for Honor Lock There is a practice quiz set up in Canvas – PLEASE take it sometime between now & Wednesday 2/19 I will also have time in class Monday 2/17 for you to take it Please take the practice quiz on the device you are going to use for Exam 1 to ensure the Chrome add-in is installed and to ensure your device will work with Honor lock Note that Honor lock is generally NOT compatible with iPads If you’re interested in borrowing a laptop for the semester or for exams in 349: https://www.library.wisc.edu/steenbock/services-at-steenbock/computers/laptops/ https://it.wisc.edu/services/computer-lending-program/ Notecards You can bring one 3x5-inch or 4x6-inch notecard of notes front & back The exam bank for Exam 1 has ~150 questions in it and you’ll be assigned 25 Each question is worth 2 points What Are Questions Focused On? Not focused on memorizing definitions or diagrams Equations will be provided Focus is understanding processes and systems and how to design considering our users As well as how we could analyze existing systems to find pain points and work to fix them How to Prepare? First, this is all covered in the welcome slides The part on “How to Succeed in 349” But let’s reiterate what I wrote out there very briefly in case you still have questions Slides A good place to start is the slides I have put a lot of time into creating the slides using information from the book and a lot of examples The slides provide a skeleton of the topics we are covering They also pose a lot of questions and introduce terms and examples As you look through the slides, can you answer these questions? Can you give me an example of the terms used, in your own words? Questions to Answer For example, here is a slide from intro to HFE Can you write down an example of a high-risk domain, a workplace, and a consumer product? Then, can you explain why the examples you pick fit into those categories? What do the length of the lines in these triangles mean? Why is emphasis put on each of these areas for each type of domain? If you can’t answer these types of questions, flag that slide Reviewing For anything you’ve flagged, you can reference your own notes or go back to Canvas Each topic page includes what sections of the book are referenced in the slides You can use the book to help you fill in gaps; a lot of what is in the book, I go over in class during lecture The book also has a lot of end-of-chapter questions that you may find useful if you are someone who likes practice quizzes, etc. I do not make practice exams for 349, but we will go over some sample questions at the end of the review Review Activity After you have gone over the slides and referenced your notes or the book for the places you are confused, if you are STILL confused about something, pop by my office and we can talk about it There is also a ‘review’ activity that can potentially earn you some extra credit Writing your own exam questions Review Structure I’ve gathered some of the big ideas from each topic here to help refresh your memory of what we’ve discussed so far Keep in mind that anything we have covered is fair game for the exam, not just the review selection I will provide any relevant diagrams For tables, like the time scales or required illumination, I don’t expect you to memorize the values Rather, be able to understand how items are related Which is longer, perception reaction time or forming habits? Which type of task/environment requires more illumination? Topic 1: Intro to HFE The Human Element The goals are to improve jobs and products, improve safety and efficiency, and focus on the human experience and health These goals are influenced by a variety of physiological, psychological, and social factors Since we work heavily in the human side of design, another key area within human factors is understanding bias in design and common design process shortcomings We’ll consider a variety of examples of human factors problems and solutions Ergonomics, accidents, healthcare, and social factors What is Human Factors? Human factors engineers aims to make technology work for people Early developments focused on improving workplace productivity and efficiency During World War II more pilots died because of human error than died in combat Later, the field expanded to consider the user experience in terms of satisfaction With the rise of in-home technology and the Internet, the field was forced to evolve even further Human Error is a Symptom of Poor Design This is a good example of what can happen when human factors engineering is neglected. All systems include people and meeting their needs is the end goal of engineers and designers If a system doesn’t work for people, it doesn’t work Human factors helps us stop playing the blame game and identify unrecognized needs that can help avoid mishaps and improve user experiences Domains of Human Factors Branches Individual Engineering psychology Physical Ergonomics & biomechanics Biomedical engineering Anatomy & physiology Architecture Industrial, civil & mechanical engineering Organizational Macro-ergonomics Cognitive Cognitive science & behavior Industrial & organizational psychology Human-computer interactions and computer science Work System Model Technology & Tools Person- Centered With processes, Outcomes these Organization People Environment interactions Organizational produce & Employee- outcomes Centered Outcomes Tasks Goals of Human Factors Human Factors Design Cycle & Design Thinking Create Understand Evaluate Two Approaches Person-Centered Systems-Centered Focuses on individuals Focuses on the conditions in which Blames human error including the problems occur inattention, carelessness, or Works to build defenses to avert forgetfulness opportunity for errors or mitigate Methods to combat include their effects campaigns, rewriting procedures, Methods to combat include disciplinary measures, blaming, creating better systems and shaming Target is the system (teams, tasks, Target is the individuals workplaces, tools, and organization) Redistribution of Error Autopilot systems designed to remove the pilot from certain flight operations to help eliminate error The idea is that the computer is better than the human at certain tasks: Navigation Course tracking Holding altitude However, if pilots do not fully understand the autopilot system, the errors are simply redistributed System Design Processes: Vee Process Often used in the design of high-risk systems Plan-Do-Check-Act Cycle Used to enhance workplace efficiency and production quality Act Plan Check Do Scrum Process Often used for consumer software products like smartphones and web applications Human- Matching methods and demands often requires balancing the speed accuracy tradeoff Centered Overriding principle: center the design process around people A system or product must meet user needs and be Design compatible with their abilities Systems Thinking A holistic perspective (systems thinking) is important to human- centered design Systems thinking can improve user experience and help us avoid unintended consequences We can simplify the human-centered design process into three major phases Prototyping Understand User focus – what does the user want & need? Create Prototype focus – how can we make this happen? Evaluate Usability focus – does it work? Usability Tests Conducted multiple times as the interface is modified Each round of testing and modification can bring about improvements Designers expect many iterations of their design Emphasis is on identifying useful functions and user interactions, not aesthetics Task Analysis Collecting data Direct observation Accident analysis Interviews with people involved/witnesses Since accidents usually result from several coinciding breakdowns, methods such as the “Five Whys” can help identify multiple causes Time – motion studies Improving performance of manual work Contextual inquiry Reveals user needs through careful observation Performing Task Analysis Define the purpose and identify required data Collect task data Interpret task data Innovate from task data Categories of Information Hierarchical relationships Identify new ways of doing things Information flow Specify interface content Sequence and timing Specify efficient interactions Location and environmental context Impact task difficulty with physical layout Limitations of Data Collection All methods have limits Combinations of methods can compensate One big limit is that all these methods capture existing behavior We can go beyond describing tasks by evaluating underlying characteristics of the environment and control requirements of the system Task Hierarchy Diagram Example Activity Diagram Example Sequence Diagram Example Types of Analyses Environment and context analysis Workload analysis Safety and hazard analyses Function allocation analysis Usability Heuristics 1. Visibility of system status 2. Match between system and real world 3. User control & freedom 4. Consistency & standards 5. Error prevention 6. Recognition over recall 7. Flexibility & efficiency of use 8. Aesthetic & minimalist design 9. Helping users recognize, diagnose, & recover from errors 10. Help & documentation Quality Function Deployment Cost Benefit Analysis Sometimes, human factors is not considered a necessary expense for a company o You may find yourself in the position of having to justify the work being done Cost/benefit analyses can be used to demonstrate the value of the efforts Purpose of Evaluation Evaluation identifies opportunities to improve a design so that it serves people’s needs more effectively Formative evaluation vs. summative evaluation Experimental Research Methods Steps in Conducting an Experiment: 1. Define your problem and hypothesis 2. Specify your experimental plan 3. Perform ethical analysis and look for areas of potential bias 4. Conduct the study 5. Analyze the data 6. Draw your conclusions Experimental Bias Bias can occur in the planning, data collection, analysis, and publication phases of research Some major sources of bias in clinical research include: Flawed study design Selection bias Interviewer bias Misclassification of exposure or outcome Citation bias Experimental Designs Multiple Group Designs You may use a two-group design; however, this isn’t always adequate. Factorial Designs Evaluating more than one independent variable or factor in a single experiment. Experimental Designs Continued Between-Subject Designs All the independent variables are between-subjects Within-Subject Designs Sometimes you may want subjects to participate in all the experimental conditions. Multiple Dependent Variables Sometimes you want to measure how casual variables affect several dependent variables at once. Selecting Participants Your study population should represent the population or group you’re interested in If you’re studying pilot behavior, you would want to pick a sample of pilots who represents the pilot population in general You may be interested in one age group, one ethnic group, and so on Representative Subsets You also want to ensure you select a range of different groups of people for every stage of your study or testing stage for your design There could be hidden bias in your design or a huge usability issue that you don’t discover until it’s on the market, which is bad Experimental Control Confounding Variables Influences both the dependent variable and independent variable Causes a false association One way to alleviate effects of these is randomization Data Analysis Now you need to determine whether the dependent variable(s) changed as a function of the experimental conditions or treatments Two types of statistics: Descriptive statistics Inferential statistics Beware of statistically significant findings & jumping to conclusions Conclusions Even more vital are your conclusions from the data This is true in naturalistic science and math, too Your results are meaningless if you cannot draw reasonable conclusions from them Drawing conclusions from statistical results requires careful judgment and communication Type I and II errors Statistical Analysis Focusing only on Type I or II errors can lead to issues Small participant numbers can influence usefulness of statistical analysis Statistical vs. practical significance Usability Testing Learnability Efficiency Memorability Errors Satisfaction Properties of a Good Study The quality of a study depends on its validity Construct validity Internal validity External validity Timescales: Longer Timescale Cognitive Process Consequence Years Expertise (10,000 Expertise requires 10 years of deliberative practice and shifts hours) decision processes Months Habits (2 months) Consistently performing an activity over ~2 months creates an automatic routine that requires effort to suppress Days Deliberating A big decision requires effort & time (1 – 10 days) Hours Circadian rhythm (24 Cycles that govern sleep and influence cognitive performance hours) when awake Minutes Vigilance decrement Monitoring is effortful and stressful and can only be sustained for a (5-20 minutes) limited time Timescales: Shorter Timescale Cognitive Process Consequence Seconds Working memory Items in working memory decay without rehearsal and decay (15-30 sec) interruptions prevent rehearsal Unbroken attention to The limits of sustained attention defines a natural task duration a task (6-30 sec) Physiological present Max. time between events to be perceived as part of a whole; (2.5-3.5 sec) longer delays lead people to start another activity Easy sentences have 14 words (3.3 sec @ 250 wpm) Reaction to Expectations strongly influence response time and unexpected unexpected events events require more time (1.0-2.0 sec) Sub-Seconds Event perception (100 A system must respond within 100 ms of a mouse click to avoid ms) noticeable delay Perceptible sound gap Maximum dropout duration in an auditory signal (1 ms) Light Intensity We can measure or specify the hue of a stimulus reaching the eye by its wavelength Measuring brightness is more complex A source can be characterized by its luminous intensity or luminous flux But we also care about illuminance and brightness Light Intensity Physical Quantities of Light Luminous flux 1 candela or 12.57 lumens (lm) Illuminance 1 foot candle (fc) (lm/ft2) or 10.76 lux (lm/m2) Luminance 1 foot lambert (fL) Reflectance R = luminance/illuminance How Much Illumination is Required? IESNA Category Space & Task Type Example Illumination (lux) Orientation & Simple Visual Tasks: A Public space with dark surroundings Parking lots 20 – 30 – 50 Orientation & Simple Visual Tasks: B Simple orientation for short visits Storage spaces 50 – 75 – 100 Orientation & Simple Visual Tasks: C Simple, occasional visual tasks Hallways, stairways, restrooms, elevators 100 – 150 – 200 Common Visual Tasks: D Tasks with high contrast and large size Simple assembly, rough machining, reading 200 – 300 – 500 Common Visual Tasks: E Tasks with high contrast and small size or low Office, library, supermarket, kitchens 500 – 750 – 1,000 contrast and large size Common Visual Tasks: F Tasks with low contrast or very small size Difficult assembly, poorly reproduced text, 1,000 – 1,500 – 2,000 painting, polishing, operating room High-Demand Visual Tasks: G Tasks with low contrast or very small size over Very difficult assembly 2,000 – 3,000 – 5,000 prolonged period High-Demand Visual Tasks: H Exacting tasks over a very long period Very precise assembly 5,000 – 7,500 – 10,000 High-Demand Visual Tasks: I Tasks near perceptual threshold – very small or Paint inspection, operating table 10,000 – 15,000 – 20,000 very low contrast Calculating Illuminance Variable Meaning E Illuminance F Luminous flux of each lamp (lm) 𝐹 𝑥 𝑁 𝑥 𝑈𝐹 𝑥 𝑀𝐹 𝐸= N Number of lamps 𝐴 UF Utilization factor to reflect light reflection on room surfaces; UF ranges from 0 – 1, where 1 = perfect delivery of We can calculate illuminance at light from the lamp to the work surface and 0.85 is representative a work surface MF Maintenance factor to reflect age – related decline in efficiency, as well as dirt and dust accumulation A Area of work surface (m2) Eye Anatomy Key terms 1. Cornea 2. Pupil 3. Ciliary muscles 4. Retina 5. Rods 6. Cones 7. Fovea 8. Optic nerve Visual Angle Image size on the back of the eye is expressed by its visual angle 𝐻 𝑉𝐴 = 2 𝑥 arctan( ) 2𝑥𝐷 H = height of object D = distance to object in same units as height What is the visual angle of the width of a 12-inch computer screen viewed at a distance of 24 inches? Remember to convert radians to degrees Rods and Cones You have two types of photoreceptor cells. Rods & cones Each has six distinctly different properties Rods and Cone Concentration in the Eye Adaptation Two types of adaptation From light to dark From dark to light Which do you think is quicker? How do we tell the color of an object? Do humans have night vision? Visual Acuity The limits of visual acuity are related to the distribution of cones in the fovea and optical properties of our eyes Acuity is expressed as a ratio Limits of visual acuity have consequences for visual processing Acuity Limits & Size Requirements Task Situation Visual Angle (arcminutes) Physical Size Distance Limit of simple visual 1 for details 0.87 cm 6.1 m acuity 5 for letters 750-pixel width of 14.2 degrees (57.6 5.79 cm 34 cm “Retina” display pixels/degree) General text – Bond Rule 24 0.007 x Distance 40 cm Fluent reading (e.g., 12 (smallest) 0.14 cm (4 points) 14.0 cm book) 180 (largest) (40 points) specified as x-heigh, font size approximately double Cockpit & vehicle displays 24 0.40 cm 58 cm Critical markings 15 – 25 0.25 – 0.42 cm 58 cm Street name signs 9.5 15.2 cm 54.9 cm Contrast Sensitivity Contrast Difference in luminance between two objects. Contrast Sensitivity Minimum contrast that can be detected by the human eye (below this level we see no difference between objects). Visual Patterns The Michelson contrast of visual pattern is the ratio of the difference between the luminance of light and dark areas 𝐿 −𝐷 𝐶= 𝐿+𝐷 C = Michelson contrast L = luminance of light area D = luminance of dark area Contrast and Age Effect of Age on Contrast Needed 400 350 Relative Contrast Required 300 250 200 150 Contrast Required 100 50 0 20-30 30-40 40-50 50-60 60-70 Age (years) Accommodation Your eyes focus images into the foveal region of the retina Accommodation is the manipulation of the lens to focus an image onto our fovea Myopia & Presbyopia Astigmatism Indirect & Direct Glare Color Vision Color vision depends on good illumination Some users also have color vision deficiencies Many computer graphics use color to discriminate lines Design for monochrome first; use color redundantly We’ll discuss more during display design Cognitive Influences on Visual Perception Design Implications How do we consider aging & older users? If designing for dim environments, what should we change? When is color coding useful? Can color serve as the primary signal? What happens when our visual perception isn’t clear? Visual Search & Detection What we do when we are using our eyes to locate something. Two types of eye movements Sometimes search strategies are serial But we don’t always search serially Targets & Noise Targets and nontargets (noise) Many searches are serial Each item inspected in turn (target, or no?) We can predict the time to detect a target 𝑁𝑥𝐼 𝑇= 2 T = time to detect a target N = number of targets I = time to inspect each target Signal Detection Theory What are some examples of signal detection tasks Signal Detection Theory is binary Operators must discriminate signals from noise SDT Outcomes Sensitivity & Bias Influences on human detection performance Sensitivity Response bias We can think of these two as reflecting bottom-up and top- down processes Adjusting Sensitivity & Beta Adjusting Sensitivity The higher the value of d’ the further the signal and noise curves are separated from each other Shifting Response Bias: High β means it is shifted to the right Low β means it is shifted to the left Response Bias – what does each of these look like? What happens to our graph? A conservative inspector An average inspector A risky inspector Anatomy of the Ear Sound The stimulus for hearing is sound Just Noticeable Difference 𝐾 𝑥 ∆𝐼 𝐽𝑁𝐷 = 𝐼 Loudness and Pitch Loudness Pitch Decibels (dB) & dBA Permissible Noise Exposure 𝑇 = 8 𝑥 2(90−𝐿)/5 T = permissible time in hours L = A-weighted sound pressure level in dBA Physical Characteristics of Sound Energy intensity (I) in dB 𝐼 𝑃2 10 𝑥 log( ) ~ log( 2 ) 𝐼0 𝑃0 𝐼0 = 10−12 𝑤𝑎𝑡𝑡𝑠/𝑚2 Sound pressure level (L) in dB 𝑃 𝑃2 20 𝑥 log = log( 2 ) 𝑃0 𝑃0 𝑃0 = 2 𝑥 10−5 𝑁𝑒𝑤𝑡𝑜𝑛/𝑚2 Sound Field Like light, sound propagates from its source and reflects off the surfaces it hits Sound intensity decline 𝑑2 𝐿2 = 𝐿1 − 20 𝑥 𝑙𝑜𝑔10 𝑑1 Properties of Space Reflection is a consideration in sound, too What do we call reflection? What are three important effects? Types of Noise Steady State Impulse Noise Noise Problems Masking Startle Response Temporary or permanent threshold shifts (hearing loss) Can negatively affect work performance via annoyance and stress Example: pilot headset quality Hearing Loss Intense sounds can cause selective hearing loss at frequencies that correspond to cilia at certain locations ear. Two types: Temporary Threshold Shift (TTS). Permanent Threshold Shift (PTS). Protection Unit Hearing Loss Hearing loss may be grouped into two categories Conductive loss Sensorineural loss Risks for Hearing Loss Sound intensity Type of noise Duration of exposure Protections in place Related diseases Noise and Performance Effects How to Control Noise At the source Along the path At the host A UD I TO RY ALARMS Issues with Auditory Alarms How do we avoid the issues described in the previous example? Design Guidelines Start with user, task, and environmental analysis When are aural warnings preferred? When are we worried about users perceiving them? Be Careful: Cry Wolf Effect What is the danger of the cry wolf effect? What are five ways to mitigate it? Other Senses Visual and auditory senses are of greatest implications for the design of human-machine systems Other senses are important to the human experience, but have not played as big of a role in design What does this include? Tactile & haptic sense Proprioception & kinesthesis Vestibular senses Touch Under the skin we have sensory receptors that respond to pressure on the skin This information is relayed to the brain We can see the importance of these other sensory channels in a few examples Proprioception & Kinesthesis A rich set of receptor systems in our muscles and joints convey information to the brain The proprioceptive channel is tightly coupled with the kinesthetic channel Vestibular Senses Located in the inner ear are two sets of receptors In the semicircular canals and in the vestibular sacs Associated with the three axes along which the head can rotate, there are three semicircular canals aligned to each axis Vestibular senses play two important roles here What do we use them for? Sample Exam Question 1 1. How does masking relate to glare, which we discussed in Chapter 4 (visual perception)? a) Both masking and glare can cause users to miss important signals from displays or the environment b) Both masking and glare improve perceptual processing speed c) Masking does not relate to glare at all Sample Exam Question 2 2. We are designing a fire alarm for a public building such as a grocery store. What frequency range should we select? a) 20 – 400 Hz b) 1,000 – 4,000 Hz c) 15,000 – 20,000 Hz Sample Exam Question 3 3. We are designing a radar control room for operators managing air traffic. Radar controllers must work in the dark in order to see the radar screens. We want to install a light in the hallway leading into the radar room. What do we need to consider when designing this light? a) We need to use a violet light because rods are insensitive to long wavelength light (like red) and people won’t be able to see the light unless we use a short wavelength light b) We need to use a red light because rods are insensitive to long wavelength light (like red) and we don’t want to ruin their light to dark adaptation c) We need to use a white light so that when people step into the hallway, they have quicker dark to light adaptation d) Any color of light is fine Sample Exam Questions 4 & 5 4. Why is it important to utilize the usability heuristic of recognition rather than recall? a) We want to place the burden of pulling critical information from the memory on the users b) We do not want to place the burden of pulling critical information from the memory on the users c) It is equally fine to rely on recognition and recall 5. What aspects are explored in an environmental analysis? a) Software and hardware, displays and controls b) What tasks are performed in what order by who and how long they take c) Lighting, temperature, protective equipment/clothing including gloves, goggles, hard hats, airflow, physical layout of floors/workstations d) How people communicate; who talks to who, the flow of information, team dynamics