# Data Analysis

> Analyze datasets reproducibly, validate quality, calculate defensible metrics, and produce clear artifacts.

- Skill: `nafeeur/data-analysis` (Agent Skill)
- Install (CLI): `npx skillmds@latest add nafeeur/data-analysis`
- Raw SKILL.md: https://api.skillmd.com/api/skills/nafeeur/data-analysis/raw
- Safety review: pending
- Works with: Claude Code, Claude.ai, OpenAI Codex
- Category: Coding & Dev Tools
- Author: nafeeur (https://skillmd.com/u/nafeeur)
- Updated: 2026-09-17
- Page: https://skillmd.com/skills/nafeeur/data-analysis

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# Data Analysis

- Inspect schema, types, missingness, duplicates, units, time zones, and sampling before calculation.
- Keep raw data immutable and make transformations explicit.
- Use robust statistics and state assumptions; distinguish correlation, prediction, and causation.
- Validate totals and joins against independent checks.
- Generate editable outputs and label filters, denominators, date ranges, and uncertainty.
- Save the script or query that produces each reported result.