Ergonomics Exam 1 Flashcards
Fitting the task to the person.
Human Factors and Ergonomics
- Safety
- Performance
- Satisfaction
Goals of HFE
- Understand
- Test
- Design
HFE Design Cycle
Behavior of people depends on situation.
Systems Thinking
Slow and detailed design process.
Vee Process
Incremental improvement design process.
Plan-Do-Check-Act Cycle
Rapid design process.
Scrum / Agile
What, why, and how tasks are performed.
Hierarchical Relationships
Who performs the task, what feedback.
Information or Part Flow
When and what order are tasks performed.
Sequence and Timing
Where and under what physical conditions are tasks performed.
Location and Context of Task
Get evaluation from 3 to 5 HFE experts individually for a broad and informal assessment of the design.
Heuristic Evaluations
Ask questions while performing the series of tasks to identify potential problems.
Cognitive Walkthrough
Compare design alternatives to find the most usable system.
Usability Testing
Manipulate certain factors / conditions to measure human behavior to understand human in a context.
Technique Selection
Variables that are deliberately changed during the study.
Independent Variables
Measure the effects of variables changed.
Dependent Variables
Transforming light waves into nerve impulses.
Vision
Light wavelength.
Hue
Light Amplitude
Brightness
Purity of Color
Saturation
Amount of energy radiated by a light source.
Luminous Intensity (I) / Luminous Flux
Amount of light falling on a surface.
Illuminance (E)
Amount of light reflected off or by a surface.
Luminance / Brightness (B)
Ratio (%) of luminance by illuminance.
Reflectance (R)
Tool for measuring illuminance.
Luxmeter
Tool for measuring luminance.
Photometer
Parts of eye that are used for motion detection, are sensitive to light levels (light and dark) and help you see in the dark.
Rods
Parts of the eye that are used for fine detail and respond to color.
Cones
Glare that arises from reflected light.
Indirect Glare
Glare that arises directly from the light source.
Direct Glare
Light with longer wavelength and lower color temperature.
Warm Light
Light with shorter wavelength and higher color temperature.
Cool Light
Relationship between object size and distance.
Visual Angle
Ability to resolve small details.
Visual Acuity
Ratio of the difference between the luminance of light and the dark areas to the total luminance.
Contrast
Processing that deals with knowledge, experience, desires, goals, context, and bias.
Top-Down Processing
Processing that deals with stimulus, the senses, acuity recognition based on individual details, and data.
Bottom-Up Processing
How much eye muscles have moved to focus.
Accomodation
How much eyes have rotated in.
Convergence
Difference between right and left eye view.
Binocular Disparity
Eye movements through the visual field.
Visual Search
Smooth following of moving target.
Pursuit
Abrupt movements from one place to the next.
Saccadic
Where a target might be.
Expectancy
Search is parallel or all at once rather than serial.
Conspicuity
Unwanted sound.
Noise
Energy waves through any elastic medium.
Sound
Vibrations associated with sound are detected as slight variations in pressure.
Amplitude
Sound power per unit area, measured in dB (decibels).
Sound Intensity (Sound Pressure Level)
Any of the techniques used to construct scales relating physical stimulus properties to perceived magnitude.
Psychophysical Scaling
Smallest change or difference in sensory stimulus that person can reliably detect.
Just Noticeable Difference (JND)
Tool that measures workers’ exposure to sound levels over time.
Noise Dosimeters
Relates perceived change to actual change in stimulus.
Weber’s Law
Loss of sensitivity to a signal when noise is present.
Sound Masking
Amount of loss of hearing after noise source has terminated.
Temporary Threshold Shift
Occupational deafness from prolonged, cumulative high-intensity noise exposure.
Permanent Threshold Shift
A workers’ daily exposure to occupational noise normalized to an 8 hour day.
Time Weighted Average (TWA)
Deals with sense of touch and position.
Haptics
Feeling from sensory receptors in the fingers and skin.
Tactile (Touch)
Feeling from sensory receptors in muscles, joints and tendons.
Kinesthesis (Position)
Sense of motion by limbs.
Proprioceptive
Convey information on linear and angular acceleration.
Vestibular Senses
The capability to process and distinguish simultaneous sources of sensory information.
Selective Attention
Too much information at once.
Load Stress
Information presented too quickly.
Speed Stress
SEEV
- Salience
- Effort
- Expectancy
- Value
A cognitive process involving trying to pay attention to several tasks at the same time.
Divided Attention
High-level cognitive mechanism of human beings to allocate attention for certain tasks.
Controlled System
Full attention to one task, then to other.
Task Switching
Time to switch from ongoing task.
Interruption Lag
Time to get back up to speed on the ongoing task.
Fluency Resumption
Time to switch back to ongoing task.
Resumption Lag
Temporary, attention-demanding storage, used to retain new information.
Working Memory
The storehouse of facts about the world and how we do things.
Long-Term Memory
Subsystem that deals with words and sounds.
Phonological Loop
Subsystem that deals with visual imagery.
Visuospatial Sketchpad
Subsystem that deals with events and experiences.
Episodic Buffer
A set of adjacent stimulus units tied together by associations in the subject’s long term memory.
Chunk (Memory Units)
Memory that can’t be put into words, you just do it.
Procedural Memory
Memory of knowing a fact.
Semantic Memory
Memory of remembering a specific instance.
Event or Episodic Memory
Remembering to perform a planned action or intention at the appropriate time.
Prospective Memory
A behavior that has been repeated many times.
Habit
The high-level mental processes that build on the stages of information processing.
Macrocognition
Thinking about one’s own thinking.
Metacognition
People’s awareness and understanding of dynamic changes in their environment.
Situation Awareness
Intuitive, automatic, and highly-practiced decision process.
Skill-Based
Heuristic decision process.
Rule-Based
Analytical, based on mental model decision process.
Knowledge-Based
Fast, involuntary, and associative decision making route.
System 1
Slow, controlled, and rule following decision making route.
System 2
Rational, optimal, or normative decision making model.
Traditional
Decision making model that describes what people actually do.
Descriptive
Comparing the expected value of outcomes, based on probabilities of the event occuring.
Expected Value Theory / Decision Trees
Measures the attractiveness / preference of each outcome for a set of alternatives.
Multi-Attribute Utility Theory
Models how people make effective decisions quickly in complex situations.
Recognition Primed Decision Making (RPD)
Present information and/or feedback.
Displays
Enable inputs to operate the system.
Controls
Determine the nature of task to be supported.
Task Analysis
Identify what users need to know for task and system operation.
Information Analysis
Map physical properties with operator requirements.
Design the Display
Visual display that measures trend, rate of change, and approximation.
Qualitative Readings
Visual display that measures precise numeric values.
Quantitative Readings
Critical information should be obvious.
Salience Compatibility
Separate pieces of information that user needs to integrate or compare should be presented close together.
Proximity Compatibility Principle
Make the display look like what it is representing.
Principle of Pictorial Realism
Make the display parts move in a way consistent with system operation.
Principle of the Moving Part
Display type that supports understanding of direction and rate of movement.
Analog Display
Display type that supports precise reading.
Digital Display
Display where relevant feature emerges from combination of graphical features.
Configural Displays
Display that’s superimposed on visual field.
Heads-Up Display
Knowledge that relies on highly salient landmarks to orient.
Landmark Knowledge
Knowledge that uses point-to-point navigation with visual triggers.
Route Knowledge
Knowledge that has an internalized cognitive map through sufficient experience.
Survey Knowledge
It takes longer to respond to many equally likely options, compared to a situation with one or two likely options.
Hick-Hyman Law
Complex movements of greater length and small target size lead to more information.
Fitts’s Law
Given a fixed information processing capacity, people can be accurate or fast, but not both.
Speed-Accuracy Tradeoff
People process information at a fixed rate.
Information Theory
It’s more efficient to require several complex choices than many simple choices.
Decision Complexity Advantage
Time required to rapidly move from a starting position to a final target area.
Movement Time
Perceive error and try to correct.
Closed Basic Tracking Loop
Movement of control specifies position.
Zero Order
Movement of control specifies change (velocity).
First Order
Movement of control specifies rate of change (acceleration).
Second Order
Amount the input is multiplied by to produce an output.
Gain
