human factor

Q: What is the formal definition of Human Factors (HFE)?

Understanding interactions among humans and system elements, applying theory, principles, data, and methods to optimize well‑being and system performance.

Q: What is the simple definition of ergonomics?

The design and engineering of human‑machine systems to enhance human performance.

Q: What is an example of ergonomics?

Opening a laptop to check your email.

Q: What are the three types of human‑machine systems?

Manual systems, mechanical systems, automated systems.

What is the classic distinction between Human Factors and Ergonomics?

Human Factors = cognitive (“above the neck”); Ergonomics = physical (“below the neck”).

Q: Where is Human Factors found?

Academia, industry, government (including the U.S. military).

Q: Why do we need Human Factors?

Human intuition is often incorrect; intuition doesn’t guide design; human error is a symptom of poor design.

AFFORDANCES & ACTION ERRORS

Q: What did J.J. Gibson propose?

A: Objects have properties that indicate what actions are possible — affordances.

Q: What did Norman (1988) contribute?

A: Applied affordances to human‑machine interfaces; what users perceive as possible actions.

GOALS OF HUMAN FACTORS

Q: What are the three goals of Human Factors?

A: Safety, performance, satisfaction.

EARLY HISTORY

Q: What did early sensory psychophysics study?

A: Speed of mental processing, nerve impulse timing, stimulus judgment, subtractive logic.

Q: What did Bryan & Harter (1898) study?

A: Learning curves for telegraph operators.

Q: What shifted during WW2?

A: Focus moved from selecting the best personnel to improving equipment.

EMERGENCE OF THE FIELD

Q: What happened in the 1940s?

A: Labs and institutes appeared; psychology branches formed in aviation and engineering.

Q: What caused rapid growth from 1980–present?

A: The internet and tragic incidents caused by poor HF design.

BAD DESIGN EXAMPLES

Q: What major accidents illustrate poor HF design?

A: Three‑Mile Island and Chernobyl.

RESEARCH METHODS

Q: What are the steps of experimental research?

A: Define question → generate hypotheses → design → conduct → analyze → conclude → communicate.

Q: What is an independent variable?

A: What the researcher manipulates.

Q: What is a dependent variable?

A: What is measured.

Q: What are the three types of variables?

A: Stimulus, behavioral, subject.

Q: What are the three sources of variance?

A: Experimental, extraneous, error.

Q: How do you control extraneous variables?

A: Eliminate, randomize, or include them.

Q: What is correlational research?

A: Identifies relationships; correlation ≠ causation; confounds possible.

Q: What is descriptive research used for?

A: Complex real‑world systems where control isn’t possible.

VALIDITY & RELIABILITY

Q: What is reliability?

A: Consistency of measurement.

Q: What is validity?

A: Whether you measure what you intend to measure.

Q: What is ecological validity?

A: Whether results apply to real‑world situations.

TASK ANALYSIS (TA & CTA)

Q: What are the four steps of Task Analysis?

A: Define purpose → collect data → interpret data → innovate.

Q: What is the goal of collecting task data?

A: See the task through the user’s eyes and understand their challenges.

Q: What does Cognitive Task Analysis focus on?

A: Cognitive skills and mental demands, not observable behavior.

INFORMATION PROCESSING & COGNITION

Q: What is the three‑stage model?

A: Information moves through sensory processing → cognitive processing → response.

Q: What are the two processing limitations?

A: Data‑limited and resource‑limited processing.

MENTAL MODELS

Q: What is a mental model?

A: A small‑scale representation of the world used to predict and understand situations.

Q: Why can mental models cause errors?

A: They can be incomplete, inaccurate, or wrong for the context.