Conciseness

Tables and checklists are mostly tight, but the body explains concepts Claude already knows ("95% confidence = p-value < 0.05. Means <5% chance result is random", the "The Peeking Problem" rationale paragraph, "Otherwise you don't know what worked"), and the "Common Mistakes" section largely duplicates "Core Principles" and "During the Test". Matches anchor 3; not 4 because the over-explanation is more than minor.

Actionability

Concrete instruction-only guidance: a fill-in hypothesis template with weak/strong examples, a sample-size quick-reference table with real numbers, named calculators, per-category variant tables, and checklists. Matches anchor 4; not 5 because the Implementation section names tools (PostHog, Optimizely, LaunchDarkly) without concrete setup steps or commands, and not 3 because the guidance goes well beyond high-level hints.

Workflow Clarity

The full lifecycle is clearly sequenced (Initial Assessment -> Hypothesis -> Design -> Sample Size -> Pre-Launch Checklist -> During the Test -> Analyzing Results -> Documentation) with an explicit pre-launch checklist and a conditional 6-step analysis checklist that catches errors ("Reach sample size? If not, result is preliminary"). Matches anchor 4; not 5 because the end-to-end sequence is implicit in section order rather than stated, and during-test monitoring offers no recovery path for technical issues.

Progressive Disclosure

The SKILL.md is a well-organized ~260-line overview that keeps a quick sample-size table inline and pushes detail to clearly signaled one-level-deep references ("For detailed sample size tables and duration calculations: See references/sample-size-guide.md"; "For templates: See references/test-templates.md"), both of which exist and deliver the promised content. Matches anchor 5: clear overview, well-signaled references, appropriate split, easy navigation.

Specificity

"Plan, design, or implement an A/B test or experiment" plus "Includes methodology, statistical significance, and metric selection" lists several actions and sub-topics, matching anchor 4. Not 5 because the verbs (plan, design, implement) are generic rather than concrete; not 3 because it goes beyond 1-2 actions with enumerated coverage areas.

Completeness

The 'what' is clear (plan/design/implement A/B tests with methodology, statistical significance, metric selection) but there is no 'Use when...' clause or equivalent explicit trigger guidance, which caps completeness at 3 per the judging guidelines. Not 4 because 'when' is entirely absent rather than merely vague.

Trigger Term Quality

Includes natural terms users say ("A/B test", "experiment", "statistical significance") but omits common synonyms like "split test", "multivariate test", and "hypothesis test", matching anchor 4 rather than the comprehensive synonym coverage of anchor 5.

Distinctiveness Conflict Risk

The experimentation/statistical-significance niche is distinct from most skills, matching anchor 4 with only minor overlap risk from generic software 'testing' skills. Not 5 because without explicit trigger phrases, bare 'test'/'experiment' wording could pull in adjacent analytics or QA skills.