14. Tests for Binary & Categorical Data скачать в хорошем качестве

14. Tests for Binary & Categorical Data

Basic Statistics: Simple Group Comparisons With Dr Helen Brown, Senior Statistician at The Roslin Institute, December 2015 *Recommended Youtube playback settings for the best viewing experience: 1080p HD ************************************************ Content: Tests for binary or categorical data Simple tests to compare groups Chi-squared test : --Based on comparing expected frequencies to observed frequencies --Most suitable for larger datasets --Popular test Fisher’s exact test : --Always suitable even if some frequencies are very small or zero Both tests may be used to compare 2 groups or equality of 3+ groups As before null hypothesis is ‘no difference between groups’ Example: Binary data -Do success rates of treatments for treating a disease in animals differ? But are there differences between pairs of treatments in success rates? Pairwise comparisons of each pair of treatments