ISE 210 Midterm Study Questions

Arrange the following in order of priority (1 = highest priority, 7 = last resort) a) provide training b) design environment c) select users d) warn users e) select design organization f) design out failure g) redesign task

1) design out failure 2) redesign task 3) design environments 4) design organization 5) provide training 6) select users 7) warn users

_____ is the minimum threshold for a person with 20/60 vision to recognize an object?

15 minutes of arc.

_______ minutes of arc = 1 degree visual angle

60 minutes of arc = 1 degree visual angle

How many steps are there in the Direct Time Study (DTS) procedure?

7 steps 1) Define and document the standard method 2) Divide the task in to work elements 3) Time the work elements to get the observed time (Tobs) 4) Evaluate the worker's pace relative to standard performance to get the performance rating. 5) Calculate normal time (Tn) = Tobs(PR) 6) Identify allowance factor (Apfd) 7) Compute standard time Tstd = Tn(1+Apfd)

Describe the relationship between curve shape and standard deviation. What happens to the curve shape with a smaller or larger standard deviation

A smaller standard deviation creates a more 'peaked' shape curve which indicates that most of the measurements are close to the mean.

What metaphor for a flashlight best describes a systematic review & a literature review, respectively?

A systematic review is like a concentrated beam with less breadth, but more intensity. A literature review has a broader beam but less intensity.

List all the factors from lecture that cause variability between populations.

Age, Sex, Racial and Ethnic group, Occupation, Generation, Transient Diurnal Variability

Which of the following statements is false in regards to static and dynamic anthropometry? a. Dynamic anthropometry accounts for range of motion in different working positions. b. When using static datasets to estimate dynamic data, height, elbow height, and forward/lateral reach distances should all be decreased by 3%. c. Static dimensions, or "structural" anthropometry, assume standard postures. d. Using ⅓ or less of the total range allows for best efficiency when considering range of motion in dynamic, or "functional," anthropometry.

B is false. When using static datasets to estimate dynamic data: a. Height should be reduced by 3%. b. Elbow height does not need to be adjusted, unless the elbow needs to be elevated for work. In that case, increase elbow height by up to 5%. c. Forward and lateral reach distances should be decreased by 33% or increased by 20% if the shoulder or trunk is allowed to move.

Why methods like "Roozbazar" are not the best for designing products for humans?

Because a percentile in one dimension isn't necessarily the same for other dimensions. Someone who is 50th percentile in one dimension will not be 50th percentile in all dimensions

Where should visual displays be placed in relation to the horizontal plane for optimal physical conform?

Between 5 degrees above to 30 degrees below the horizontal plane. The "normal" line of sight is approximately 10-15 degrees below the horizontal plane. Visual displays should be placed within +/- 15 degrees of the normal line of sight for optimal performance and physical conform.

What is the difference between reflecting a surface vs transmitting a surface?

Both are factors of luminance, reflecting or reflection is when light hits an opaque surface like a tree. L= E * R where, R = reflectance constant Transmitting or transmission is when light hits a translucent or a transparent object, like a glass. L = E * T where, T = transmittance constant

What is the absolute lowest value that humans can read at? a. 8 Lux b. 5 Lux c. 1 Lux d. 3 Lux e. Both B) and C) are valid responses

C. 1 Lux

What does it mean for contrast to be positive or negative?

Contrast is positive when the target is lighter than the background. Contrast is negative when the target is darker than the background

Keeping size constant, if you increase the distance between yourself and an object, does the visual angle increase or decrease?

Decrease

What are the 3 main approaches used to determine the percentage of the population a designer should design for. Give an example of each approach.

Design for extreme - example: a toilets seat designed to accommodate the heaviest user Design for adjustable range - example: an adjustable car steering wheel Design for average - example: ATM machine is designed for the average height user to use the device.

Explain why designing for the 90th percentile does not always mean designing for 90% of the population, and give one example of when this might be the case to explain.

Designing for the 90th percentile does not always mean designing for 90% of the population because it depends on the design goals, for example designing the size of a medication pill, might design to support the smallest throat and use 10th percentile measurement to accommodate 90% of the population.

You have just been hired by Google's Hardware product design team to assist in designing the Pixel Phone. What would be your first step in trying to determine the dimensions of the new phone?

Determine the design population based on hand size.

Define luminous intensity (I).

Electromagnetic energy emitted in a particular direction (subtended solid angle = steradian) Measured in candela (cd) = lm/steradian

What is the distinction between engineering psychology and human factors?

Engineering psychology is a discipline within psychology that seeks to understand the human mind as it relates to design Human factors is a discipline within engineering that aims to design systems accounting for psychological and physical factors that are properties of the human components.

True or false: Standard Data Systems are databases of universal work study measurements that can be applied at any company.

False

True or False: Anthropometric military data is an accurate representation of the overall population, thus it is widely used in a variety of design processes.

False, Anthropometric data for military and civilian populations differ substantially.

True or False: According to the five-times rule, distance to a light source should be lower than five times the largest dimension of the source.

False, a five-times rule states that distance to a light source should be higher than five times the largest dimension of the source and not lower.

True or False: If you have 20/20 vision, does this mean you have perfect vision?

False, if you are older and have presbyopia, you can have 20/20 vision but have a decreased ability to accommodate near objects.

True or False - Equipment designed to fit 90% of the US male population will also fit 90% of males globally.

False, racial and ethnic group variability is one of the many factors of human variability. For this example, equipment designed for 90% of US males will only fit roughly 90% of German males, 65% of Italian males, 45% of Japanese males, and 10% of Vietnamese males.

True/False: Designers should strictly follow measurements in anthropometric tables

False. Although these measurements are standardized, they may not accurately represent real life situations. Designers should thoroughly analyze the design problem and make appropriate adjustments to these values.

True/False: In designing for users, it is important to design for 100% of the population

False. Design depends on the user population and will change depending on the user population. We want to design for existing and potential users to capture the large majority of the target population. Adjustability options can increase the number of users that can be accommodated.

True or False: When designing for 95% of a population, one is always designing for the 95th percentile.

False. It varies depending on the design goals (designing for the middle, designing for the largest, or designing for the smallest), as well as other features such as sex.

True/False: A positive lens is used to correct myopia, and a negative lens is used to correct hyperopia.

False. It's the other way around (see slide 19 of Vision Pt 2). For reference: myopia = nearsightedness, hyperopia = farsightedness.

True or false: The frequency of use principle states that the components used most frequently are the most important for achieving system goals.

False. The Frequency of Use Principle states that the components that are used most frequently should be placed in the most convenient locations. The Importance Principle states that the components critical to achieving major goals should be in the most convenient locations. These are two of the seven principles for component arrangement. These goals are not always able to be met simultaneously, and workplace design must evaluate carefully the trade-offs and design accordingly.

True or false: In terms of human factors priorities, warning users should always be considered first because it is the most effective method to prevent failures.

False. Warning users should only be considered if every other priority cannot be satisfied. Try to design out any problems first before considering any other steps.

True or False: The color you perceive corresponds to the wavelength of light absorbed by the object being observed.

False. We see color based on the wavelength of light reflected, not absorbed

True or false: As background luminance increases with contrast held constant, less detail can be distinguished.

False: As background luminance increases with contrast held constant, more detail can be distinguished.

For dynamic anthropometry, why forward and lateral reach distances should be decreased?

For easy reach. Don't need to lengthen the arm/leg to the maximum

Clearance dimensions are higher-limit dimensions and should be adequate for the largest users (typically 95%) who are planning to use the workplace, and then often adjusted upward to reflect the increased space needs of a person with heavy clothes.

Incorrect. Clearance dimensions are lower-limit dimensions

Based on the Rule of Thumb for Labels and Legends, if given that lighting is >1 foot candle, is k1 with favorable reading conditions higher or lower than the k1 for unfavorable reading conditions?

Lower based on (Peters & Adams, 1959)

Describe the difference between luminous flux and luminous intensity.

Luminous flux is the total amount of visible light emitted by a light source in all directions. Luminous intensity (I) is the total amount of visible light emitted by a light source in one direction.

Your friend hires you to design an ergonomic workstation specifically for her home office. She uses multiple screens and multiple devices that needs to be plugged into the wall outlet that is a horizontal distance from the edge of her table. Her height dimensions happens to be in the 50th percentile. Is It safe to assume that her functional reach dimension will be in the 50th percentile?

No, just because she is average in her height doesn't mean the rest of her body dimensions will be in the 50th percentile

Should people make designs that encapsulate 100% of the population?

No, they should not. It is unrealistic and very expensive to design with 100% of the population in mind. A good example of this is doorways. If we wanted to design around 100% of the population then we would have doorways that exceed 8 feet. In many places 8 foot doorways would not even fit

What is the difference between proactive and reactive design?

Proactive design refers to anticipating user errors and various issues of the product before it gets to the user, while reactive design techniques aim to solve any problems of the product discovered after the design is created and used.

Name two types of human variability and explain how they impact product design

Sex variability: Women and men have different body characteristics. Men are, on average, taller and bigger than women Occupational variability: People who work in different occupations have different body dimensions. Age variability: average height varies across age groups Racial or Ethnic group variability: Different average build, body dimensions and weight across different groups Transient Diurnal Variability: height and weight can vary by small amounts at different times of day Generational Variability: average height has increased from previous generations.

Define luminance (L).

The amount of light energy reflected off the object's surface or transmitted through a transparent surface. Measured in foot-lamberts (lumens/ft^2) or nits (candela/meter^2).

Define luminous flux.

The total amount of light emitted by a source in all directions. Measured in lumens. Total luminous flux in all directions = 4π lumens

Define illuminance (E).

The total amount of light energy that falls on a surface. Measured in foot-candle (lumen/ft^2) or lux (lumen/m^2)

Andrea is starting her own business making jewelry. Her designs make use of many small gemstones that must be precisely placed. She was looking online for ideas on how to make her workspace more ergonomic, and she read that her desk should be at elbow height when she is sitting down. Is this good advice for Andrea? Why or why not?

This is not good advice for Andrea, as the task she is going to be doing at her workspace requires high precision. High precision work requires the work surface to be raised higher than elbow level to a place where the work can be seen clearly without bending forward with their neck and back.

True/False: Anthropometry is used in the field of HF in order to match the physical dimensions of workplaces and products with the body dimensions of intended users.

True

True or False — While designing a gym, Alex decides to dedicate a corner of the building to cardio equipment and another corner for resistance training equipment. By congregating all the cardio equipment closely together in one location and all the resistance training equipment together in another location, Alex is adhering to the functional grouping principle.

True. The functional grouping principle states that components with similar or related functions should be arranged together in close proximity

Why is it better to take a proactive approach in design rather than reactive?

When you are proactive in your design you end up saving more money in costs because you have designed out any potential problems early in the process. When you are reactive costs can be higher because you may have to go back and redesign certain aspects because of errors or failures that happen in later stages of design.

What kind of method does work sampling use, and what is the ultimate goal of work sampling?

Work sampling uses random sampling of the work tasks so you can develop a proportion of time spent on different tasks. The ultimate goal is to identify the amount of time spent on certain activities.

Assuming a normal distribution, if you fall + or - 1 SD away from the mean what percentage of the population would you be a part of?

You would be among the 68.3% of the population that falls + or - 1 SD away from the mean.

What time does MOST calculate a) Normal time b) Standard time c) Observed time d) all of the above

a) Normal time

Below are examples of designing to accommodate to a size of the population (Smallest, Medium, & Largest). Assign the appropriate Design (Small, Medium or Largest) accommodation to the correct example and explain why that is the case. a. Size of a chair in an airplane. b. Push force required to open a door c. The height of the ceiling in a home d. Height of a sink

a) design for the middle - designing for either extreme would make the chair unsafe for users who are too small or large, so the middle can cover the largest range of users. b) design for the smallest - if the weakest person can push hard enough to open the door, it will easily open for anyone. c.) design for the largest - Keep the largest users from hitting their heads and all other users will be fine as well. d) design for the smallest - increased accessibility for the smallest users (and people with mobility issues) still allows access for the larger users.

What are the three elements of system thinking?

a) interconnection b) adaptation c) environment

Match the following: a. Design to accommodate middle b. Design to accommodate largest c. Design to accommodate smallest 1. Door handle height 2. Dining chair 3. Door height

a. Design to accommodate middle -> dining chair b. Design to accommodate largest -> door height c. Design to accommodate smallest -> door handle height

What factors influence illumination of an object? (Choose all that apply) a. Distance b. Angle c. The amount of lux emitted by a light source d. The surface area of the object

a. [✓] Distance - if a light source is farther away, there is less illumination on the object b. [✓] Angle - According to Lambert's Cosine Law: i. "Full" illumination occurs when surface is normal to source ( θ= 0 degrees; so cos(θ) = 1) No illumination when surface is at right angle to source (θ= 90 degrees; so cos(θ) = 0) c. [✓] The amount of lux emitted by a light source - implicitly related. If a light source emits more lux, the amount of illumination an object receives is influenced d. [X] The surface area of the object - not relevant to determine illumination

The amount of energy that falls on a surface is known as _______. a) Luminous Flux b) Illuminance c) Luminous Intensity d) Luminance

b) Illuminance

Which refractive error causes image distortion from multiple focal points on retina, and is cause by irregularity in sphericity of cornea or shape of lens? a. Hyperopia b. Astigmatism c. Presbyopia d. Myopia

b. Astigmatism

In designing to accommodate the largest, the design must: a. Accommodate the smallest person and everyone larger than that b. Accommodate the largest person and everyone smaller than that c. Accommodate the middle of the normal distribution d. Accommodate a person 2 standard deviations above the mean and everyone smaller than that

b. Design to accommodate the largest considers the largest person and everyone smaller than that. It does not necessarily have to be at 2 standard deviations above the mean.

The mean height of the population is 65 inches and the standard deviation is 2 inches. If you design to accommodate the largest, which of the following is a possible range which your product accommodates? a. 67"-71" b. less than or equal to 67" c. greater than or equal to 67" d. greater than or equal to 65"

b. Designing to accommodate the largest means that the product will work for everyone at or below the largest anthropometric size selected to fit the product. In this case, the largest was 1 std dev above the mean.

You are at a poster session at the HFE conference (in person). You and your friend notice someone walk into the hall, your friend says "Wow, that's a really bright green blazer, I feel like it is burning my eyes". Is your friend referring to the blazers: a. Luminous intensity b. Luminance c. Illuminance d. Luminous flux

b. Luminance

Which of the following is NOT one of the three ways to design with Anthropometry? a. Designing to accommodate the middle b. Designing to accommodate the smallest c. Designing to accommodate the youngest d. Designing to accommodate the largest

c) Designing to accommodate the youngest

What are the three domains of specialization in the field of Human Factors/Ergonomics? a) physical factors, social factors, psychology b) macro ergonomics, social factors user factors c) physical factors, cognitive factors, macroergonomics d) environmental factors, cognitive factors, physical factors

c) physical factors, cognitive factors, macroergonomics

Human error is a symptom of a) poor organization b) poor color c) poor design d) poor product

c) poor design.

Assume that a bed is designed at the 45th percentile for a user group at 175 cm, what percent of the population will not be able to fit on this bed? a) 45% b) 22.5% c) 65% d) 55% e) None of the above

d) 55%; Anyone above 175 CM will not be able to fit on this bed as the bed is designed for anyone at 175 CM and below.

According to Signal Detection Theory, which of the following DOES NOT increase the vigilance decrement of a user? (In other words, which of the following does not make a user less vigilant?) a) A target's signal strength is reduced b) The event rate of the target is increased c) The payoff associated with hitting more targets d) supplying the operator with a 'visual template' of what the target will look like

d) supplying the operator with a 'visual template' of what the target will look like.

Which of the following is not a source of variability in anthropometric measurements? a. Age b. Sex c. Racial or ethnic group d. Education level e. Occupation

d. Education level. All other groups were covered in the text as examples of human variability. In addition to age, sex, racial or ethnic group, and occupation, generational variability and transient diurnal variability were also mentioned.

Which of the following is NOT a refractive error? a. Hyperopia b. Astigmatism c. Myopia d. Presbyopia

d. Presbyopia. Refractive error refers to the condition when the combined efforts of cornea and lens cannot bring an image into focus, resulting in a blurry image. Presbyopia is not a refractive error because someone with presbyopia can still have 20/20 vision on a standard test.

Which of the following is NOT a monocular depth cue? a. Relative height b. Occlusion c. Atmospheric perspective d. Stereopsis e. Motion parallax

d. Stereopsis

Which of the following statement(s) are true about Anthropometry? a) Anthropometry is the study and measurement of human body dimensions. b) Anthropometric data can be used to assess the stress imposed on worker's joints and muscles during the performance of work. c)Anthropometry can be used to develop guidelines for accommodating the body dimensions of the potential workforce. d) Anthropometric data can be applied to the design of consumer products. e) All options are true. f) None of the options are true.

e) all options are true