Paper prototype

A paper prototype is a set of hand-drawn screens, each on its own sheet or card, that a person can “use”. The participant taps a button with a finger; a facilitator, playing the computer, swaps in the sheet that would appear next. No code and no software, just pens, paper and someone to shuffle it.

What it is for

It exists to test an idea while changing it is still nearly free. You find out whether the flow makes sense, whether the labels mean what you think, and whether a whole step is missing, before anyone has built anything. Because everyone can see it was drawn five minutes ago, participants are also more willing to say it is confusing.

How it differs from a wireframe

A wireframe is a tidy layout document, often made digitally and shown for review. A paper prototype is meant to be used, not looked at, and its roughness is a feature. The tool does not matter much; what matters is that it can be put in front of a user and operated. Compare it with a clickable prototype, which gives more realistic feedback on interaction and timing at a much higher cost.

In practice

Make a sheet for every state you want to test, including an error, because the participant will find the one you forgot. Keep a pile of blank sheets to write on live. And be willing to redraw between sessions: the real benefit is changing the design after participant two rather than collecting five reactions to the same flaw in usability testing.