✈ Flight Control by
(demo)
The Concord Superstore experimentation program operated at a mean throughput of 47 concurrently active experiments during the period ending June 2, 2026. Twelve experiments reached conclusive posterior thresholds (P(beat control) ≥ 0.95 or Bayes Factor ≥ 10), representing a 33.3% increase in decisional velocity relative to the prior 30-day window. Program-level cumulative expected uplift on 90-day customer lifetime value, derived by marginalizing over the joint posterior of all concluded experiments, is estimated at +8.3% (95% HPD: [+5.1%, +11.6%]) relative to the universal holdout cohort.
Five experiments produced Bayes Factors exceeding 10 ("strong" evidence on the Jeffreys scale), with the Featured Products Algorithm reaching BF₁₀ = 110.3 — unambiguous evidence of efficacy. Three experiments are recommended for early termination due to Bayes Factors near unity, indicating no detectable treatment effect under the current prior specification. The program-level joint Bayes Factor is 14.2, representing strong evidence that the portfolio as a whole generates positive CLV impact (prior period: 9.8, "moderate" on Jeffreys scale), a directionally encouraging trend.
No experiments in the current window produced credible evidence of harm (P(harm) > 0.05), defined as a posterior probability of negative uplift exceeding the pre-registered threshold. The universal holdout group (N = 45,082; 10% of eligible traffic) maintained stable behavioral baselines throughout the window, supporting validity of the holdout design.
Mean experiment duration declined 10.2% month-over-month, from 42.1 days (May) to 37.8 days (June). This reduction is attributable to three independently verifiable contributing factors:
(1) ROPE-based stopping rules. Replacement of fixed-horizon designs with Region of Practical Equivalence (ROPE) stopping criteria, adopted in Q1, reduces expected runtime by an estimated 18% for experiments where true effects fall clearly outside the ROPE. The current ROPE is set to ±0.5% relative uplift on primary CLV metrics.
(2) Increased traffic allocation. Daily traffic allocated to experimental units increased 14% relative to the prior period, reducing the number of days required to achieve target posterior precision.
(3) Prior calibration improvements. Tighter Beta priors derived from the 142-experiment historical corpus reduce posterior variance, enabling earlier decisional convergence for experiments in well-studied surface areas (e.g., checkout flow).
⚠ Monitoring note: Posterior predictive checks indicate 3 of 12 recently concluded experiments may have been underpowered for detecting effects below +2.0%. Recommend tightening ROPE bounds from ±0.5% to ±0.3% for high-traffic page types where small effects are commercially significant.
Beta-Binomial models; continuous outcomes (revenue, CLV, average order value) use Normal-Inverse-Gamma models. Posterior distributions are approximated via No-U-Turn Sampler (NUTS) with 100,000 posterior draws following a 2,000-step warm-up phase. Bayes Factors are computed using the Savage-Dickey density ratio. All reported credible intervals are 95% Highest Posterior Density (HPD) regions and should not be interpreted as frequentist confidence intervals. Expected Loss is defined as E[max(0, Δθ)] under a 0–1 loss function. The program pre-registers a stopping threshold of Expected Loss ≤ 0.15 for early termination decisions. Stopping for futility is triggered when BF₁₀ < 1/3 ("moderate evidence for H₀").
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1
Expedite rollout of Featured Products Algorithm (BF₁₀ = 110.3). Under any reasonable loss function, continued allocation of traffic to the control condition is suboptimal. The posterior expected loss from delaying rollout is estimated at $2,100 per day in foregone CLV at current traffic volume. Recommended action: initiate production deployment within 5 business days.Evidence grade: Decisive (Jeffreys scale). Posterior mean uplift: +11.4%. HPD excludes zero with >99% probability.
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2
Terminate Order Summary Redesign and Express Checkout CTA. Both experiments have reached Expected Loss thresholds exceeding the pre-registered stopping criterion of 0.15. BF₁₀ values of 1.0 and 0.9, respectively, indicate the observed data are no more consistent with H₁ than with H₀. Continued runtime accumulates opportunity cost without meaningful posterior updates given current traffic allocation.Recommended action: Stop both experiments. Reallocate traffic capacity (+~18K users/day combined) to underpowered experiments in the register.
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3
Tighten ROPE bounds on high-traffic checkout pages from ±0.5% to ±0.3%. Posterior predictive calibration of 3 recently concluded experiments indicates the current ROPE may have allowed premature stopping for experiments with true effects in the [0.3%, 0.5%] range. At Concord Superstore's transaction volume, a 0.3% CLV uplift represents approximately $380K in annualized incremental revenue — commercially material and above the threshold of indifference.This change will increase expected runtime for borderline experiments by approximately 8–12 days but will reduce Type-S error rate in the checkout surface area.
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4
Extend Category Navigation Rework by 14 days; increase traffic allocation by 10%. Current BF₁₀ = 1.6 ("anecdotal" evidence) with a posterior mean of +1.3% and a 95% HPD that crosses zero. The experiment is not futile — the posterior does not favor H₀ — but remains underpowered for a definitive conclusion. Posterior predictive simulation estimates that 14 additional days at +10% traffic allocation yields a 73% probability of reaching BF₁₀ ≥ 3 ("moderate" evidence).Recommended action: Approve 14-day extension. Do not stop for futility; BF₁₀ > 1/3 does not satisfy the pre-registered futility threshold.
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5
The 10.2% MoM reduction in experiment duration is consistent with program velocity targets, but requires ongoing monitoring. The program Bayes Factor trend (9.8 → 14.2 MoM) is encouraging, but the reduction in duration has occurred simultaneously with an increase in decisional throughput — this correlation is consistent with both genuine efficiency gains and with mild underpowering. Recommend implementing a
posterior_width_at_stoptracking metric to distinguish these hypotheses prospectively. A pre-registered posterior width threshold of ±2.5% relative CLV would provide a principled stopping criterion independent of runtime.Evidence grade for the velocity improvement itself: Anecdotal. Recommend 2 additional periods before drawing causal conclusions about contributing factors.