What is your process for cleaning data?

As a data analyst, data preparation, also known as data cleaning or data cleansing, will often account for a majority of your time. A potential employer is going to want to know that you’re familiar with the process and why it’s important.

In your answer, give a short description of what data cleaning is and why it’s important to the overall process. Then walk through the steps you typically take to clean a data set. Consider mentioning how you handle:

  • Missing data
  • Duplicate data
  • Data from different sources
  • Structural errors
  • Outliers

Interviewer might also ask:

  • How do you deal with messy data?
  • What is data cleaning?