If the null hypothesis that there are no differences between the classes in the population is true, the test statistic computed from the observations follows a χ 2 frequency distribution. In the standard applications of this test, the observations are classified into mutually exclusive classes. For contingency tables with smaller sample sizes, a Fisher's exact test is used instead. Pearson's chi-squared test is used to determine whether there is a statistically significant difference between the expected frequencies and the observed frequencies in one or more categories of a contingency table. The test is valid when the test statistic is chi-squared distributed under the null hypothesis, specifically Pearson's chi-squared test and variants thereof. In simpler terms, this test is primarily used to examine whether two categorical variables ( two dimensions of the contingency table) are independent in influencing the test statistic ( values within the table). Chi-squared distribution, showing χ 2 on the x-axis and p-value (right tail probability) on the y-axis.Ī chi-squared test (also chi-square or χ 2 test) is a statistical hypothesis test used in the analysis of contingency tables when the sample sizes are large.
0 Comments
Leave a Reply. |
AuthorWrite something about yourself. No need to be fancy, just an overview. ArchivesCategories |