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usability

yoo-zuh-BIL-i-tee /ˌjuːzəˈbɪləti/

nounB2TOEFLIELTS

professionaltechnicalacademic

The degree to which a product, system, or service can be used by specified users to achieve specified goals with effectiveness, efficiency, and satisfaction.

Usability is a holistic measure of the user experience. It is not just about whether a system works, but how easy, pleasant, and error-free it is for a human to operate.

The story behind the word. The word stems from the Latin 'uti', meaning to use or profit by. While 'use' has been in English for centuries, 'usability' emerged as a distinct technical term in the late 20th century with the rise of computer science and human-computer interaction (HCI).

Word relationships

user-friendliness: User-friendliness is an informal, colloquial term, whereas usability is a formal, standardized engineering and design metric.
operability: Operability refers strictly to whether a machine can be operated, whereas usability includes the psychological comfort and satisfaction of the user.

inoperability: The state of being completely unusable or broken.
cumbersomeness: The quality of being awkward, heavy, or difficult to use due to design complexity.

Commonly confused with

utility: Utility is whether a product has the right functions to solve a problem; usability is how easily and efficiently a human can execute those functions.

Word family

use (verb): To employ for some purpose; put into service.
usable (adjective): Capable of being used.
user (noun): A person who uses or operates something.

Collocations

usability testing
usability study
improve usability
usability guidelines

Example sentences

"Despite having advanced features, the software suffered from poor usability, leading to high customer frustration and a wave of refund requests." A software engineering post-mortem.
"During usability testing, nurses were able to program the infusion pump in under ten seconds without making a single error." An evaluation of a new medical device.

Memory hook

Think of 'usability' as 'use-ability'—the actual ability of an average person to use a product without pulling their hair out. Smooth, painless operation.

When not to use

Do not confuse 'usability' with 'utility'. 'Utility' is whether the product has the necessary features (what it does); 'usability' is how easily the user can actually use those features.

Fun facts

The standard ISO 9241-11 formally defines usability based on three pillars: Effectiveness (can users complete their goals?), Efficiency (how much effort does it take?), and Satisfaction (how did they feel?).