Chapter 3 of 7 · 4 practices · 3 min · 3-question quiz
Joins without surprises
A join that changes the number of rows you expected is the most common silent error in analysis. These practices check cardinality, unmatched rows and nulls every time.
5 more chapters, 20 more practices, free with an account.
You have read the open chapters of the Data Analysis Best Practices guide. Every chapter it covers is listed above, and an account opens the rest: each practice with why it matters, how to apply it and an example, with your progress saved as you tick them off. Early access is open: sign up and your account is active shortly after.
Everything here is free to learn from. A few things, like adding a roadmap, keeping a cheat sheet or asking Tauseef a question, use credits. You get 15 when you join, your first roadmap is free, and if you are learning seriously and run out, you can ask for more. Credits only make sure the platform goes to people who are actually learning.