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data-warehouse-experimentation

Running experiments out of the data warehouse instead of via dedicated experiment platforms. SQL-based assignment, exposure logging discipline, metric definitions in dbt models, statistical analysis in SQL or Python, variance reduction with CUPED, sequential testing, and the operational tradeoffs vs platforms like Statsig and Optimizely. Triggers on warehouse-native experimentation, run experiments in BigQuery, run experiments in Snowflake, dbt experiments, SQL t-test, CUPED variance reduction, exposure log, sample ratio mismatch, sequential testing, mSPRT, doubly robust estimation, build vs buy experimentation. Also triggers when the team is choosing between platform and warehouse, building warehouse-native experiment infrastructure, auditing one, or running an experiment with a custom metric the platform cannot handle.

Quality

89%

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SKILL.md
Quality
Evals
Security

Quality

Content

78%Weight 40%Scale 1-5

Reviews the quality of instructions and guidance provided to agents. Good implementation is clear, handles edge cases, and produces reliable results.

A well-structured, actionable playbook: executable SQL/Python templates, a sequenced architecture, an explicit 12-consideration checklist with validation checkpoints, and exemplary progressive disclosure to real one-level reference files. The main improvement areas are trimming narrative sections and making the CUPED/notebook snippets fully executable.

Suggestions

Trim the introductory platform discussion, the 'What this skill is for' sibling listing, and the 'Closing' section to reduce token cost without losing operational guidance.

Replace pseudocode in the CUPED section (pre_period_revenue, undefined metric arrays) with a runnable pandas/numpy snippet that loads pre-period and experiment-period metrics from the warehouse.

Add an explicit validate-retry loop for the SRM check (e.g., 'if SRM p-value < 0.001, stop, audit assignment hash and exposure log, then re-run') to make the framework's checkpoints into feedback loops.

DimensionReasoningScore

Conciseness

The sections are dense with non-obvious domain guidance (exposure-fire timing, salt isolation, SRM discipline) rather than concepts Claude already knows, but the introductory platform discussion, the sibling-skill listing in 'What this skill is for', and the essayistic 'Closing' section are padding that could be trimmed. Efficient overall with minor over-explanation, so 4 rather than 5.

4 / 5

Actionability

Most guidance is executable: working SQL for hash assignment, the dbt metric model, and the Welch t-test, plus runnable Python for t-tests and power analysis. Minor gaps remain — the CUPED snippet uses undefined pseudocode ('pre = pre_period_revenue(user_id)', 'warehouse.query(...)') and the flag-service SQL references a hypothetical table — keeping it below fully copy-paste-ready.

4 / 5

Workflow Clarity

The architecture section gives a clear data-flow sequence, and the 12-consideration framework provides a checklist with explicit validation checkpoints (SRM check before computing any metric, pre-registered stop criteria, power analysis before running). It falls short of 5 because error-recovery loops (e.g., 'if SRM fails, fix and re-check') are named as pitfalls rather than wired into an explicit validate-retry sequence.

4 / 5

Progressive Disclosure

The body is a well-organized overview with all detail pushed to 8 real, one-level-deep reference files, each signaled inline at the end of its section and consolidated in an annotated 'Reference files' section. All referenced paths exist in the bundle, and navigation is easy.

5 / 5

Total

17

/

20

Passed

Description

96%Weight 40%Scale 1-5

Based on the skill's description, can an agent find and select it at the right time? Clear, specific descriptions lead to better discovery.

A strong description: third-person, concrete about capabilities, with an explicit and comprehensive trigger list covering natural user phrasings. The only weakness is slight overlap with a sibling skill on the platform-vs-warehouse decision trigger.

DimensionReasoningScore

Specificity

The description lists multiple concrete actions — 'SQL-based assignment, exposure logging discipline, metric definitions in dbt models, statistical analysis in SQL or Python, variance reduction with CUPED, sequential testing' — with comprehensive coverage of the skill's capabilities, matching the anchor for multiple specific concrete actions.

5 / 5

Completeness

It explicitly answers both 'what' ('Running experiments out of the data warehouse instead of via dedicated experiment platforms...') and 'when' ('Triggers on... Also triggers when the team is choosing between platform and warehouse, building warehouse-native experiment infrastructure, auditing one, or running an experiment with a custom metric the platform cannot handle').

5 / 5

Trigger Term Quality

Trigger coverage is comprehensive and natural: 'run experiments in BigQuery, run experiments in Snowflake, dbt experiments, SQL t-test, CUPED variance reduction, exposure log, sample ratio mismatch, sequential testing, mSPRT, doubly robust estimation, build vs buy experimentation' — these are exactly the phrases a user facing this need would say, with synonyms and tool names included.

5 / 5

Distinctiveness Conflict Risk

The niche is clear and distinct (warehouse-native experimentation execution), but the trigger 'choosing between platform and warehouse' overlaps with the sibling skill 'experimentation-platform-orchestrator' that the body says covers that decision in detail — a minor conflict risk with a closely related skill, so not a 5.

4 / 5

Total

19

/

20

Passed

Validation

93%

Checks the skill against the spec for correct structure and formatting. All validation checks must pass before discovery and implementation can be scored.

Validation — 15 / 16 Passed

Validation for skill structure

CriteriaDescriptionResult

frontmatter_unknown_keys

Unknown frontmatter key(s) found; consider removing or moving to metadata

Warning

Total

15

/

16

Passed

Repository

rampstackco/claude-skills

Path

skills/data-warehouse-experimentation/SKILL.md

Reviewed

Table of Contents

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