chi-square test
The definitions used in this glossary of terminology either have been provided by the authors of the articles, or have been extracted wholly or in part, or paraphrased from the following sources: The American Medical Association Encyclopedia of Medicine, Charles B. Clayman, MD, Medical Editor, Random House, New York, 1989; Biotechnology from A to Z, 2d Edition, William Bains, Oxford University Press, New York, New York, 2002; A Dictionary of Genetics, 6th Edition, Robert C. King and William D. Stansfield, Oxford University Press, New York, New York, 2002; Dorland's Illustrated Medical Dictionary, 29th and 30th Editions, W. B. Saunders Company, Philadelphia, 2000, 2003; Genes VII, Benjamin Lewin, Oxford University Press, New York, New York, 2000; The Gale Encyclopedia of Genetic Disorders, Volumes I and II, Stacey L. Blachford, Ed., Thomson Learning, New York, New York, 2002; The Merriam-Webster Dictionary, Merriam-Webster, Inc., Springfield, Massachusetts, 1997; Molecular Biology of the Cell, 3rd Edition, Bruce Alberts, et al., Garland Publishing, 1994; The Random House Dictionary of the English Language, Unabridged Edition, 1966; Webster's Ninth New Collegiate Dictionary, 1991.
DEFINITION:
- chi-square test
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Any statistical hypothesis test that employs the chi-square (X2) distribution, especially two tests applied to categorical data: the X2-test of goodness of fit, which tests whether an observed frequency distribution fits a specified theoretical model, and the X2-test of independence or homogeneity, which tests whether two or more series of frequencies (the rows and columns of a contingency table) are independent. In both cases the test statistic is the sum over all categories of the squared difference between the observed and expected frequencies divided by the expected frequency, under the null hypothesis. The sampling distribution of this X2-statistic approaches the X2-distribution as the sample size increases, under the null hypothesis.
Used in 1 Term definition
Used in 1 Term definition