A girl biting on a pencil stressed about a quiz. There is text on the image. It reads: What data team member are you? Take the quiz to go find out!

Chi-Square Test

Share icon

A statistical way to check if two things are related or if your data is just messing with you.

Chi-Square Test

The Chi-Square Test is a statistical method used to determine whether there is a significant association between two categorical variables. It is particularly valuable in the fields of data science and artificial intelligence for tasks such as feature selection and hypothesis testing. The test compares the observed frequencies of occurrences in a contingency table to the expected frequencies, which are calculated under the assumption of independence between the variables. This method is widely employed in various applications, including market research, social science studies, and medical research, where understanding the relationships between categorical data is crucial.

Data scientists and analysts utilize the Chi-Square Test to validate assumptions about data distributions and to identify potential relationships that may inform model development. For instance, in machine learning, it can help in selecting relevant features by assessing their independence from the target variable. The test is essential for ensuring the robustness of conclusions drawn from categorical data, making it a cornerstone of statistical analysis in data-driven decision-making.

Example in the Wild

When discussing the impact of marketing strategies, a data analyst might quip, "Using a Chi-Square Test is like checking if my cat's preference for tuna over chicken is just a coincidence or a culinary conspiracy!"

Alternative Names

  • Chi-Squared Test
  • Chi-Square Test of Independence
  • Chi-Square Goodness of Fit Test

Fun Fact

The Chi-Square Test was first introduced by Karl Pearson in 1900, and it has since become a fundamental tool in statistics, proving that sometimes the best way to understand data is to simply see if it "fits" the expected pattern!

Chi-Square Test
An ad for Secoda which says, experiencing metadata migraines? Ask your data engineer about Secoda.
URBAN DATA DICTIONARY IS WRITTEN WITH YOU
Submit a word
The ad reads "When it comes to your valuable data, don't leave it to chance! Contact us". With a mother and baby looking at a computer together while sitting in a kitchen.An image of a book mock up called "The State of Data Governance in 2025" by Secoda. Below the image there's text that reads" The state of Data Governance in 2025. Download the report."