UX Glossary · L
Learnability
How quickly a new user can become competent, as distinct from how fast an experienced user works.
Learnability is how easily someone can accomplish a task the first time, and how quickly they improve with repetition. Nielsen lists it as one of the components of usability, alongside efficiency, memorability, errors and satisfaction.
The tension with efficiency
Learnability and efficiency frequently pull against each other, and this is one of the most consequential trade-offs in product design.
An interface with everything visible and labelled is easy to learn and slow to operate repeatedly. An interface built on shortcuts, gestures and dense controls is fast for an expert and impenetrable on day one. Consumer products usually optimise for the first; professional tools used eight hours a day should usually optimise for the second.
Getting this backwards is a recognisable failure: enterprise software that is simple to demo and infuriating to use daily, because it was optimised for the buyer’s first impression rather than the operator’s tenth thousand.
Serving both
The usual resolution is layering: a discoverable path for everyone, with accelerators alongside it. Menu items that display their keyboard shortcut teach the fast path while the slow one is being used.
In practice
Measure both. Time on first attempt tells you about learnability; time on the fifth attempt tells you about efficiency, and a design that improves one at the cost of the other has made a decision that should be deliberate.