Exploratory data analysis , or EDA, is the habit of looking at your data before you compute anything from it. This guide covers what to look at, the research showing why it is not optional, and what it looks like on real projects you can open and read.
It exists to prevent one specific failure, and that failure has nothing to do with math. An analyst computes an answer from data they never looked at. The numbers come out precise, confident and wrong, because the data had a quirk nobody checked for.
Detective work vs courtroom work
Data work has two distinct modes, and mixing them up causes most analytical failure:
Exploratory (detective)
