usability-testing

Use when planning or conducting usability tests — writing test scripts, defining tasks, selecting participants, analysing findings, and turning observations into design actions

Usability Testing

Testing with real people is how you find out if the design works — not by looking at it, but by watching someone use it.

When to Use

After design-builder produces a working prototype
Before declaring a design complete
When the design-critic flags persona coverage gaps
When assumptions about user behaviour need evidence

Process

Step 1: Define What You're Testing

Write 3-5 task scenarios that map to the core jobs in the brief. Each task:

Starts with a realistic trigger — "You just bought a new plant and want to add it to the app"
Has a clear success condition — "The plant appears in your list with a watering schedule"
Does not tell the user how — never say "tap the + button"

Step 2: Select Participants

Recruit 5-8 participants. At minimum include:

1 person who uses a screen reader
1 person over 60
1 person who is not a native speaker of the interface language
1 person with low tech confidence

Reference inclusive-personas for the ability spectrum.

Step 3: Choose Method

Method	When to use	Minimum participants
Moderated think-aloud	New flows, complex interactions	5
Unmoderated remote	Simple tasks, large sample	8-12
Guerrilla (hallway)	POC validation, time-constrained	3-5
Accessibility audit with AT users	After build, before ship	2-3