Stop
The pymetrics (Harver) Stop game is a rapid go/no-go task—not a stop-signal task. You respond to red circles and withhold on green circles while repeated go trials build response momentum.
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Updated
How to play
Press the spacebar when a RED circle appears. Do nothing when a GREEN circle appears.
Every red circle also has stripes and a P; every green circle has dots and an H, so the rule never depends on color alone.
Each circle lasts briefly. A missed red and a press on green both count as errors.
On a touch device, use the full-width TAP FOR RED / P button in place of the spacebar.
In the real assessment
The real assessment is generally described as showing no right/wrong feedback. This practice version flashes a subtle ✓ or ✕ after each circle; the exact real trial count remains unconfirmed.
Skills assessed
Create an account to save your results. A pymetrics pass includes unlimited replays. All results stay free.
Score improvement across practice attempts
Across our matched practice data, the median candidate improves their score by +14% between their first and fifth practice attempt on a game — with no employer ever seeing practice data.
Read the full methodologyMedian pymetrics score lift by practice attempt
Median paired change vs. first attempt on scored pymetrics practice games. Observed practice association — not a hiring-outcome guarantee.
Stop practice guide
Read the rules, scoring context and practice strategies for this game.
Read the Stop guideGameAssessmentPrep is an independent practice platform. We are not affiliated with pymetrics, Harver, or any employer. Our simulations are reconstructions for practice purposes.