, non-parametric tests课件.ppt

The paired t-test, non-parametric tests, and ANOVAJuly 13, 2004;Review: the Experiment (note: exact numbers have been altered);The results;Confidence interval (more information!!);The Paired T-test;The Paired T-test;The differences are treated like a single random variable;Example Data;Example 2: Did the control group in the Oak School experiment improveat all during the year?;Confidence interval for annual change in IQ test score;Summary: parametric tests;Non-parametric tests;Non-parametric tests;Example: non-parametric tests;Example: non-parametric tests;Enter data in SAS…;Jenny Craig;Atkin’s;t-test doesn’t work…;Statistical tests to compare ranks:;Wilcoxon rank-sum test;Wilcoxon “rank-sum” test;*Tests in SAS…;Wilcoxon “signed-rank” test;*Tests in SAS…;What if data were paired?;Enter data differently in SAS…10 pairs, rather than 20 individual observations;*Tests in SAS…;ANOVAfor comparing means between more than 2 groups;ANOVA (ANalysis Of VAriance);The “F-test”;amenorrheic;Group means and standard deviations;;The F-distribution;The F-distribution;ANOVA Table;ANOVA=t-test;ANOVA summary;Question: Why not just do 3 pairwise ttests?;Multiple comparisons;Multiple comparisons;Correction for multiple comparisons;Non-parametric ANOVA;Reading for this week