UI and UX Optimization · Testing changes · Component

The measure

What the change is meant to improve, agreed in advance — because deciding afterwards means the winning metric is chosen from the results.

The deliverable

What it is

A test with several measures and no primary one always produces a winner, because something moved. That is not evidence.

The measure and the effect size that would matter should both be written before the change is built.

One level in

What it is made of

Each element is a constituent part of the component. Follow one to see the attributes it carries.

  1. The primary

    The one measure the test is judged on.

    3 attributes: Measure · Because · Agreed

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  2. The effect size

    How much improvement would matter.

    3 attributes: Minimum effect · Reason · Value if achieved

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  3. The guardrails

    What must not get worse.

    3 attributes: Guardrail · Acceptable movement · Breached

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A test with several measures and no primary one always produces a winner. That is not evidence.