Rental Car - Answers Plot: Pilot ran to familiar plane but the entire cockpit was different and all the
buttons were in the wrong place. He couldn't figure out how to fly it in time.
HF Concepts:
Heuristic checklist: Be consistent and follow standards
Business in Bhopal - Answers Plot: Head of company was arrested for corporate liability. Plant had
deteriorating conditions, operators didn't write in English as managers required. Only way to tell if there
was a problem was to notice it physically. No one had emergency procedures. Superintendent came
after anything could be fixed. Toxins spread to surrounding neighborhoods.
HF Concepts: Micro/Macro ergonomics
Chutes and Ladders - Answers Plot: Electric line touched a pole, which killed a worker. Had to find out
how and why it could have happened. The pipe was so long and flexible that it was easy to swing high
and touch the low power lines. The man was trying to get out a rabbit in the pipe and it hit the line.
HF Concepts: Human Centered Design Process, Understanding the user, task, and environment using
general and specialized methods, HTA , Field Observation
Leap of Faith - Answers Plot: Airshow showing off new flight. Wanted to show off its new automation.
The pilot turned off the automation because to do the low flyby the automation would have overridden
his controls. He became overconfident because he didn't realize automation was overriding his
commands when flying. Led to him being out of practice and causing the crash.
HF Concepts: Automation, Overconfidence, Complacency
Wizard of Wall Street - Answers Plot: Clerk got a last minute transaction. Misread sheet and sold 11
million shares of stock instead of 11 million dollars worth of stock. System allowed you to execute
transaction in minutes. The safeguard of someone else checking didn't work. Caused dow-jones to
plummet.
HF Concepts: Automation, Fitt's list, Increase work load
Set Phasers on Stun - Answers Plot: Man supposed to get radiation treatment. Technician delivered it in
separate room without seeing the status of the client visibly or auditorily. Radiologist made a mistake
and fixed it so quickly that the computer was designed not to recognize it and it went into proton beam
mode. Computer said there was a malfunction so she administered another beam electrocuting the
patient. Although machine told operator it was operating, correctly, she couldn't see the result of her
actions.
HF Concepts: Visibility of system, Lack of HCD principles, Swiss Cheese Model, HFACS
,An Act of God - Answers Plot: Power operator in charge of power for NYC. Lightening hit one of the lines.
He wasn't aware that certain lines were hit and out of commission. He wasn't getting the help he
needed and couldn't expect to get help. One of his ties was overloaded. His in-city generators were slow
at making up the power because he was talking on the phone too long to talk to them. Failure of
operator to take the necessary actions.
HF Concepts: Swiss Cheese Model, HFACS ( Precondition for unsafe act: Condition of Operator,
Supervisor issues , Unsafe Acts), Human error/operator error
In Search of the Lost Chord - Answers Plot: Nurse connected cord from the IV pump and not the heart
monitor. The size and shape were similar to the chord from the heart monitor. When she plugged the
connectors a lethal current went into the girls heart.
HF Concepts: Swiss Cheese Model HFACS (Preconditions of unsafe acts: Environment. Condition of
operator. Unsafe Acts: Perceptual error and decision based error)
Murphy's Law and Newton's Law - Answers Plot: Trying to launch the Orion rocket into space. Every
action to get the rocket in the air had an equal and opposite reaction. Wanted to use the tester to make
sure the igniter was connected and working properly. Battery flew out into igniter and rocket blasted off
horizontally killing people
HF Concepts: Swiss Cheese Model, HFACS: (Supervisory, Preconditions, Lack of communication!)
Peppermint Twist - Answers Plot: Waitress went to pour watermelon shots but picked up a glass that
held pink liquid that looked similar and poured people shots of cleaning fluid, which contained sodium
hydroxide. The cleaning fluid was delivered in a plastic gallon and it made the red warning label not
noticeable. You could easily pour it out; nothing stopped you from doing that. The bar ran out of dish
soap so it used some of the industrial cleaning fluid and put it in a glass that looked identical to a drink
bottle.
HF Concepts: Description Similarity Slip, Perception is biased by experience. (Familiar perception to
patterns/frames biases what we see), Perception biased by current context and perception biased by
goals, Gestalt Principle: Similarity , Human color perception:(Didn't use color-opponent channels. Red
against pink makes it hard to distinguish important messages, which led to people thinking it was okay
to use at bar. Inability to discriminate color and there was no other features such as smell that could
discriminate fluid from alcohol.)
Lee - Answers Automation Use, Misuse, Disuse, and Abuse article
o Automation designers frequently fail to account for how people adapt to the introduction of
automation, leading to unanticipated negative consequences concerning satisfaction, performance, and
safety.
o Automation designed to enhance safety does not always enhance safety and that as automation
becomes more sophisticated, the role of the human becomes more important.
,o Automation Use:
• Use of automation refers to operators engaging automation to perform functions they might
otherwise perform manually.
• Appropriate use can enhance safety and performance
• Depends on a complex interaction of factors that include, workload, cognitive overhead, trust in
automation, self-confidence, and risk.
Automation Misuse - Answers • Misuse concerns situations in which operators rely on automation when
the automation performs poorly
• In these situations, operators might over trust the automation; use heuristics to engage automation in
situations that are not always appropriate, or fall pretty to automation biases that make them less
attentive to contradictory information.
• Monitoring failures: operators tend to neglect automation breakdowns.
• Situations in which people use automation in ways the designers did not anticipate.
Automation Disuse - Answers • Disuse concerns situations in which operators fail to engage automation
when it could enhance performance.
• Operators are often slow to accept automation because it threatens their way of life, they have not
developed trust in its capability, or the automation lacks the needed functionality.
• Under-trust leads to disuse
Automation Abuse - Answers • Abuse concerns situations in which automation is designed and
implemented without paying sufficient attention to tis effects on the operators.
• Often occurs when designers or managers believe that replacing unreliable people with reliable
automation will reduce errors and enhance efficiency.
• Replacement fallacy: underlies the assumption that failures can be avoided by automating the
operator's role ignores the role people play in accommodating the unexpected and in maintain a safe
and efficient system.
• Leaves people unsupported in accommodating the situations that the automation cannot
accommodate.
• Automation abuse often occurs because designers create automation that has a high degree of
authority and autonomy, leading to surprises as the automation responds in ways that the operator
does not expect.
Shutte - Answers Design Considerations for Human-Machine Interactions
, -In engineering terms, the human operating system was designed to not do everything that the rational
mind knows that it should
-Yet, when it comes to humans, we design systems that expect and count on the human not making
typical human errors.
-Task errors are the result of the normal functioning of a human being. We tend to ignore the
knowledge that humans are likely to fail.
-Human error: should be described as the inevitable negative consequences of normal human behavior
that was not accounted for in the design of the system
-Role-based function allocation may lead to a more complementary and collaborative use of
automation.
Color Design Recomendations - Answers oConsider pre-existing associations
oUse color to indicate status (red/green)
oUse color to draw attention
oUse color to organize information
•Colors denote similarities or categories.
oUse color consistently within your system.
oUse color consistently across similar systems.
oConsider ambient lighting
Top Down Processing - Answers Context driven reading
oKnowledge, expectations, context, and goal driven perception
oPeople don't see the physical thing for its physical features, but rather how you perceive the meaning
•B or 13 depends on CONTEXT
oPeople are biased to see what they expect
Human Machine Systems - Answers A system in which an interaction occurs between people and other
system components.
Interaction of human and something in the engineered world operating together to achieve a goal.
Human Factors - Answers Scientific discipline concerned with the understanding of interactions among
humans and other elements of a system