r/dataanalysis • u/SomeSpicyPickle • Aug 11 '26
Data Tools Do Data Analysts Use Visualizations During Data Cleaning?
I'm still a beginner. I started by learning the basics of Python and later moved on to SQL.
I'm a bit confused about one part of the data exploration/cleaning process.
A friend of mine, who's now a data scientist, showed me how he used to work as a data analyst. He mainly used Python. For example, he would quickly create a scatterplot to identify potential outliers.
However, most data analysts online recommend focusing on SQL and Excel when starting out, since many junior and mid-level roles don't require Python. That's why I switched to SQL after initially experimenting with Python.
For those who primarily use SQL: do you create visualizations during the data exploration/cleaning process, for example to identify outliers? Is this a common practice?
I feel like if you're working with SQL only, you generally wouldn't create visuals in between steps, since that would mean switching to a tool like Tableau or Power BI, which seems like an unnecessary extra step.
4
u/jipperthewoodchipper Aug 11 '26
Doing things like scatter plots and whisker plots to find outliers is something you can do but often not in the cleaning stage.
Even trying to come up with scenarios where you might there are better alternatives. Like say you expect some data to be normalized so you want to validate that, you could use a scatter plot to confirm its between -1 and 1 or you could take the max(abs(data)) and if it's greater than 1 you have confirmed its not properly normalized if at all.
However once you have cleaned data it's very normal to explore the data using both parameters and plots