chi-square: meaning, definition, pronunciation and examples
C1/C2Technical/Academic
Quick answer
What does “chi-square” mean?
A statistical method used to test hypotheses about the distribution of categorical data or the independence of two variables.
Audio
Pronunciation
Definition
Meaning and Definition
A statistical method used to test hypotheses about the distribution of categorical data or the independence of two variables.
Refers to the statistical test, its resulting value, or the underlying probability distribution. In research, it's a fundamental tool for analyzing count data.
Dialectal Variation
British vs American Usage
Differences
Spelling differences are minimal. 'Chi-square test' is more common in American English, while 'chi-squared test' is often preferred in British statistical writing, though both are understood globally.
Connotations
Neutral statistical term. In non-academic contexts, it may be perceived as complex or intimidating.
Frequency
Exclusively high frequency in academic papers, research reports, and data science contexts. Extremely rare in general conversation.
Grammar
How to Use “chi-square” in a Sentence
The researcher performed a [chi-square] on the data.The [chi-square] was significant, χ²(2) = 10.5, p < .05.Vocabulary
Collocations
Examples
Examples of “chi-square” in a Sentence
adjective
British English
- The chi-squared value indicated a poor fit for the model.
American English
- A chi-square analysis revealed a significant association.
Usage
Meaning in Context
Business
Rare, except in market research analytics (e.g., 'We used a chi-square to see if region was independent of product preference').
Academic
Very common in social sciences, medicine, biology, and any field using categorical data.
Everyday
Virtually never used.
Technical
Core term in statistics, data science, and research methodology.
Vocabulary
Synonyms of “chi-square”
Neutral
Weak
Vocabulary
Antonyms of “chi-square”
Watch out
Common Mistakes When Using “chi-square”
- Pronouncing 'chi' as 'chee' (like in 'Chicago').
- Using it for continuous data (e.g., height, weight).
- Saying 'a chi-square' when referring to the distribution generically (uncountable: 'the chi-square distribution').
FAQ
Frequently Asked Questions
Both are accepted. 'Chi-square' is often used as the noun ('run a chi-square'), while 'chi-squared' is common as an adjective ('the chi-squared statistic') in British English, but the distinction is not strict.
No, not directly. Chi-square tests require raw frequency counts, not percentages or proportions. The test operates on the actual observed numbers.
It means the observed distribution of counts is statistically unlikely to have occurred if the null hypothesis (e.g., no association, or a perfect fit) were true. It suggests an association or a lack of fit.
A test of independence checks if two categorical variables are related in a contingency table. A goodness-of-fit test compares observed counts in a single categorical variable to counts expected from a theoretical distribution.
A statistical method used to test hypotheses about the distribution of categorical data or the independence of two variables.
Chi-square is usually technical/academic in register.
Chi-square: in British English it is pronounced /ˈkaɪ skweə/, and in American English it is pronounced /ˈkaɪ skwer/. Tap the audio buttons above to hear it.
Learning
Memory Aids
Mnemonic
Think 'KAI-square' – a statistical 'guy' (Kai) who squares up categorical data to see if the counts fit expectations.
Conceptual Metaphor
A MEASURING STICK FOR CATEGORIES: It measures the 'distance' or discrepancy between observed counts and expected counts.
Practice
Quiz
For which type of data is a chi-square test most appropriately used?