Definition of "chi-square" []

• A test statistic that is calculated as the sum of the squares of observed values minus expected values divided by the expected values. (noun)

American Heritage(R) Dictionary of the English Language, Fifth Edition. Copyright (c) 2011 by Houghton Mifflin Harcourt Publishing Company. Published by Houghton Mifflin Harcourt Publishing Company. All rights reserved.

• "Goodness of fit between different documents was obtained by computing the so called Q value from the standard chi-square hypothesis test."
• ""Using the chi-square statistic," observes one professor, "Obama's and Ayers's books were indistinguishable, while Obama's book was easily distinguishable from books by other authors.""
• "I did a chi-square "goodness of fit" test and got a P value of 0.18."