chi square

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chi square (χ)2

(in statistics) a statistic test for an association between observed data and expected data represented by frequencies. The test yields a statement of the probability of the obtained distribution having occurred by chance alone.

chi square (kī),

n a nonparametric statistic used with discrete data in the form of frequency count (nominal data) or percentages or proportions that can be reduced to frequencies. Used to determine differences between categories (e.g., yes-no; visits dental office every 6 months, 1 year, 2 years, 5 years); compares the observed results with the expected results to determine significant differences. May be used with many categories of response.