A/B Test Read

Compare two conversion counts with a pooled two-proportion z-test. “Likely real” means |z| is at least 1.96. Checking early inflates that call.

Visitors A

Conversions A

Visitors B

Conversions B

At a 95% bar

Likely real

Assumes you look once, at independent visitors. Checking every hour makes “likely real” show up too early.

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Frequently asked questions

What does “likely real” mean?

The absolute z-score is at least 1.96, the usual 95% bar for one planned look. It is not a full experiment design.

Why not check every hour?

Repeated looks make “likely real” appear too early. This tool assumes you look once.