chi-square test: meaning, definition, pronunciation and examples
C2Technical/Academic
Quick answer
What does “chi-square test” mean?
A statistical hypothesis test used to determine if there is a significant association between two categorical variables or if an observed frequency distribution differs from a theoretical one.
Audio
Pronunciation
Definition
Meaning and Definition
A statistical hypothesis test used to determine if there is a significant association between two categorical variables or if an observed frequency distribution differs from a theoretical one.
A non-parametric test that assesses the goodness of fit or independence by comparing observed frequencies with expected frequencies under a null hypothesis, resulting in a test statistic (χ²) that follows a chi-square distribution.
Dialectal Variation
British vs American Usage
Differences
No significant lexical or grammatical differences. Spelling of related terms may follow regional conventions (e.g., analyse/analyze).
Connotations
Identical technical connotations in both varieties.
Frequency
Equally frequent in academic and technical writing in both regions.
Grammar
How to Use “chi-square test” in a Sentence
The researcher performed a chi-square test [on the data].A chi-square test was conducted [to examine the association].Vocabulary
Collocations
Examples
Examples of “chi-square test” in a Sentence
verb
British English
- We need to chi-square these contingency tables.
- The data were chi-squared to check for goodness of fit.
American English
- We need to run a chi-square on this frequency table.
- The data were analyzed using a chi-square test.
adjective
British English
- The chi-squared value was significant.
- She presented a chi-square analysis.
American English
- The chi-square value was significant.
- He used a chi-square analysis.
Usage
Meaning in Context
Business
Rare, except in market research reports analysing survey response categories.
Academic
Very common in social sciences (e.g., psychology, sociology), medicine, and biology for analysing categorical data.
Everyday
Extremely rare; would not be used in casual conversation.
Technical
Core term in statistics, data science, and research methodology.
Watch out
Common Mistakes When Using “chi-square test”
- Mispronouncing 'chi' as /tʃiː/ (like in 'Chicago') instead of /kaɪ/.
- Using it for continuous data (e.g., height, weight) instead of categorical data (e.g., gender, yes/no responses).
- Incorrectly writing 'chi square' without the hyphen, though 'chi-squared' is also an accepted adjectival form.
FAQ
Frequently Asked Questions
Both are used. 'Chi-square' is more common as a noun modifier ('chi-square test'), while 'chi-squared' is often used as an adjective ('the chi-squared distribution'). In practice, they are frequently used interchangeably.
No. Like most statistical tests, a chi-square test can only indicate an association or relationship between variables. It cannot prove that one variable causes changes in another.
You need frequency or count data organised in a contingency table (cross-tabulation). The data should be categorical (e.g., yes/no, group A/B/C), not continuous measurements like height or temperature.
A statistically significant result (typically p < .05) suggests that the observed frequencies in your data are unlikely to have occurred if there were no actual association between the variables in the population. It provides evidence against the null hypothesis of independence or goodness-of-fit.
A statistical hypothesis test used to determine if there is a significant association between two categorical variables or if an observed frequency distribution differs from a theoretical one.
Chi-square test is usually technical/academic in register.
Chi-square test: in British English it is pronounced /ˈkaɪ skweə test/, and in American English it is pronounced /ˈkaɪ skwer test/. Tap the audio buttons above to hear it.
Learning
Memory Aids
Mnemonic
Think: 'Chi' sounds like 'kai' (key) – it's a KEY test for CATegorical data. SQUARE the differences to see if they're fair (compared to expected).
Conceptual Metaphor
A MEASURING TOOL FOR FIT (like a tailor checking if a suit fits expected measurements).
Practice
Quiz
What is the primary purpose of a chi-square test?