FA-74692 / Experiment statistics / Member archive

Complier average causal effect: Treatment outcomes are averaged over adopters · case 02

The ITT estimate mixes a per-protocol treatment mean with an intent-to-treat control mean.

Member previewVariant 2 · 3 implementations · 8 checks per implementation

Case contract

Outcome sums cover every assigned user. ITT = outcome_sum_t / assigned_t - outcome_sum_c / assigned_c. Compliance difference = took_t / assigned_t - took_c / assigned_c (control users can cross over). CACE = ITT / compliance difference when that difference is positive, else None. Nonpositive assignment counts -> None. Return [ITT, compliance difference, CACE] rounded to 6.

Why this case matters

Opt-in features have partial uptake; the effect on adopters needs an instrumental-variable estimate.

One recorded failure

Sample boundary fixture

This sample comes from the broken implementation of a controlled reproducer.

Boundary fixture	Actual	Expected	Outcome
crossover in control reduces compliance difference	`[2.0, 0.5, 4.0]`	`[0.6, 0.5, 1.2]`	Failed

MEMBER ARCHIVE

The complete case is available to members.

This record includes three runnable implementations, regression fixtures, execution results, and source hashes.

Member access is invitation-based. Sign in with your invited account to inspect the sources.