Let me share the convo:
The distinction is about why an experiment doesn’t give you a clear, actionable outcome:
Inconclusive experiment
• The experiment was run, but the data doesn’t provide enough evidence to favor one hypothesis over another.
• Causes:
◦ Too little traffic/sample size (low statistical power).
◦ High variance in the data.
◦ Poorly chosen metrics (not sensitive enough).
• Interpretation: You can’t say whether the treatment works or not — you need more or better data.
Flat experiment
• The experiment ran with enough power, and the metrics are stable, but the treatment effect is essentially zero.
• Causes:
◦ The tested change genuinely doesn’t move the measured outcomes.
◦ The feature might not impact the chosen metric (or at all).
• Interpretation: The experiment confirms the null hypothesis — there’s no meaningful difference between control and variant.
In short:
• Inconclusive = lack of evidence (data issue).
• Flat = clear evidence of no effect (treatment issue).
Do you want me to also show you how these are usually treated differently in decision-making frameworks (e.g., whether to re-run vs. discard the idea)?