Review-Gating Bias Simulator

User Population

Mean satisfaction (0–10) 6.5

Satisfaction spread (σ) 1.8

Rating-Prompt Gate

Gate threshold t 7.0

Live Stats

True mean satisfaction

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Public store rating

–

Gating bias Δ

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Routed to store

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How it works

Each simulated user carries a true, hidden satisfaction score S drawn from a normal distribution S ~ N(μ, σ²), clamped to [0, 10]. A "smart" in-app rating dialog first asks a private question ("Enjoying the app?") and only routes happy users to the public app-store rating; unhappy users are quietly diverted to a private feedback form instead. This practice is called review gating.

Gate:      S >= t  → public store rating
           S <  t  → private feedback form

Observed public rating (gated):
  E[S | S >= t] = μ + σ · φ(α) / (1 − Φ(α)),   α = (t − μ) / σ

φ = standard normal PDF,  Φ = standard normal CDF
(the truncated-normal mean / inverse Mills ratio)

Mean / spread sliders — set the true underlying satisfaction distribution of your user base.
Gate threshold — the cutoff score the smart prompt uses to decide "public store" vs "private form".
Gating ON/OFF — OFF routes every responder 50/50 regardless of score, an unbiased sample; the public rating then tracks the true mean. ON applies the threshold and the public rating rises above the true mean.

Real-world relevance: Apple's App Store Review Guideline 4.1 explicitly bans this pattern for exactly this reason — a store rating built only from pre-filtered happy users is a biased estimator of real user satisfaction, not a random sample of it.

Routed to store Routed to feedback form

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