Data Analysis Journal

Data Analysis Journal

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User Segmentation and Power User Analysis in SQL
What are user segmentation techniques? How to locate your Power users? How to do user segmentation analysis in SQL?
 • Olga Berezovsky
What “Normal” Looks Like: A Guide to Baselines - Issue 299
The starting point of every good analysis: how to define, calculate, and use baselines.
 • Olga Berezovsky
Anticipating 2026: Top Trends in Analytics - Issue 298
The key movements shaping analytics, the analyst role shift, and how to prepare for 2026
 • Olga Berezovsky
Goodbye 2025 🎄 - Issue 297
A recap of 2025, confetti, gratitude, and what’s coming next!
 • Olga Berezovsky
Refresher on Metrics and KPIs - Issue 296
An evergreen guide to the metrics you’ll use for experimentation, analysis, modeling, and forecasting.
 • Olga Berezovsky
Refresher on Visualizations - Issue 295
Charts, dashboards, and storytelling basics - what actually matters when showing data.
 • Olga Berezovsky
Refresher on Experimentation - Issue 294
A consolidated guide to statistics, tools, best practices, and advanced experimentation
 • Olga Berezovsky
November Recap: Before You Trust That Lift
Your monthly recap of the latest trends, market shifts, and updates in data science and analytics
 • Olga Berezovsky
Churn: Why Most Teams Get It Wrong - Issue 292
How to build accurate churn reporting for your product, plans, and revenue model.
 • Olga Berezovsky
Structuring Data & Analytics Teams for Real Impact - Issue 291
How org structure shapes analytics insight, governance, and the quality of every decision.
 • Olga Berezovsky
Data Analysis Journal
Data Analysis Journal
Where product, data science, and analytics intersect.
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Checklists
A/B Test Checklist
A short guide to product experimentation steps and must-know terminology.
SQL Date-Time Cheatsheet
A short guide to steps, solution, and must-know terminology
Python Pandas DateTime Reference Guide
A short guide to solutions and tips for handling DateTime cases in Python Pandas
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Tutorials
A Selection Of SQL Tutorials
A roundup of free SQL tutorials and articles to either get started with or to keep your querying skills strong.
A Selection Of Python Tutorials for Analysts
A roundup of my favorite tutorials for data analysts to either get started with or upkeep existing Python skills

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