About the author
Who writes this
My name is Michael Nocito. I am a data analyst, and every guide, lesson and drill on this site is written by me. There is no editorial team, no syndicated content, and nothing here is reprinted from anywhere else.
I spent more than ten years moving data and documents between enterprise systems. That work is unglamorous and it is where I learned the part of analysis nobody teaches: real data arrives broken, and the person who can find out how it broke is more useful than the person who can recite a formula. Leading zeros vanish. Two systems disagree about the same customer. A date column holds four different formats. I have fixed all of that under a deadline, and it is the experience the guides are built on.
I now work in SQL, Excel, Tableau and Python, and I write about the parts I use daily rather than the parts that sound impressive.
Why this site exists
I built the Analyst Prep Kit while teaching myself the analyst toolset, because the material I wanted did not exist. Tutorials showed clean data and correct answers. Interviews asked about messy data and defensible reasoning. The gap between those two things is where people get stuck, and it is the gap every guide here tries to close.
So the guides are written to be used, not admired. Each one leads with what you can do by the end of it, shows the work with real numbers, names the mistake that costs the most, and says plainly when a method should not be trusted.
How the guides are written and checked
Every guide follows the same standard, and it is deliberately strict:
Worked examples use real numbers. When a guide says a test needs 10,317 visitors per arm, that number came out of the calculation shown on the page. Figures are not rounded for tidiness or invented for illustration.
Claims that came from research cite the research. Where a guide leans on a statistical result or a published study, it names the source so you can check it rather than taking my word for it.
Limitations are stated, not hidden. Each method gets an honest account of when it misleads. A guide that only tells you what works is not finished.
Corrections are made in place. When something here is wrong, I fix the page and update its modified date rather than quietly deleting it. If you find an error, please tell me — see below.
What is free, and how the site is paid for
Every guide, kit, drill and download on this site is free to read and use, with no account required and nothing held behind a signup. Some pages carry a single advertisement, and some kits have an optional paid version. Neither changes the free content, and the details of both are in the privacy policy.
Corrections and contact
If a guide is wrong, unclear, or out of date, I want to know. Email hello.michaelnocito@gmail.com and tell me which page and what looks off. I read everything sent there and I answer.
More about my work and portfolio: michaelnocito.github.io. Code: github.com/michaelnocito.