Does it support rigorous statistical analysis?

Absolutely. It includes patterns for t-tests, chi-square tests, and calculating effect sizes like Cohen’s d to ensure data interpretations are mathematically sound.

How does this skill improve SQL writing for data analysis?

It enforces the use of Common Table Expressions (CTEs), early filtering, and includes a query optimizer to detect anti-patterns and performance bottlenecks in your SQL code.

What types of charts and visualizations does it recommend?

It follows a specific chart selection matrix to ensure the right visualization—such as histograms for distributions or scatter plots for correlations—is used for every data type.

Can it help with professional business reporting?

Yes, it provides a specific 'Insight Delivery Template' that focuses on actionable recommendations and quantified business impact rather than just presenting raw numbers.

Advanced Data Analyst

Name: Advanced Data Analyst
Author: borghei

byborghei

•

Analíticas y Monitorización

Empowers Claude to perform expert-level data analysis, including production SQL generation, statistical testing, and stakeholder-ready business reporting.

This skill transforms Claude into a senior data analyst capable of framing business questions as testable hypotheses and delivering actionable insights. It provides standardized workflows for writing optimized SQL with CTEs, profiling datasets for quality, executing statistical tests like t-tests or chi-squares, and selecting the most effective visualizations based on data relationships. Whether you are calculating cohort retention, building growth reports, or interpreting complex datasets, this skill ensures rigorous methodology and clear insight communication through a professional 'What / So What / Now What' framework.

Características Principales

01Optimized SQL generation using CTEs and window functions

02Intelligent visualization selection matrix for effective data storytelling

03Standardized insight reporting using the What/So What/Now What framework

0450 GitHub stars

05Statistical hypothesis testing and data profiling capabilities

06Comprehensive business metric calculations for growth, retention, and revenue

Casos de Uso

01Calculating month-over-month revenue growth and complex cohort retention patterns

02Automating stakeholder report generation from raw CSV, JSON, or SQL database outputs

03Running A/B test significance checks using t-tests and chi-square statistical methods

What are Skills?·How to Install

Install with 🐟 Skill.Fish

npx skillfish add borghei/claude-skills data-analyst

For use in Claude.ai and ChatGPT

Download Skill