We had 5 judges taste and rank 6 different beers. The data -shown above- are in beertest.sav. For answering which beer was rated best, a Friedman test would be appropriate because our rankings are ordinal variables. A second question, however, is to what extent do all 5 judges agree on their beer rankings? If our judges don’t agree at […]
For testing if 3 or more variables have identical population means, our first option is a repeated measures ANOVA. This requires our data to meet some assumptions -like normally distributed variables. If such assumptions aren’t met, then our second option is the Friedman test: a nonparametric alternative for a repeated-measures ANOVA. Strictly, the Friedman test can […]
The Mann-Whitney test is an alternative for the independent samples t test when the assumptions required by the latter aren’t met by the data. The most common scenario is testing a non normally distributed outcome variable in a small sample (say, n < 25).* The Mann-Whitney test is also known as the Wilcoxon test for independent samples -which shouldn’t be confused […]
SPSS nonparametric tests are mostly used when assumptions aren’t met for other tests such as ANOVA or t-tests.* Second, nonparametric tests are suitable for ordinal variables too. In rare cases they may have more statistical power than standard tests. Not sure which (nonparametric) test to use? You’ll quickly find the answer in Simple Overview Statistical Comparison Tests. Nonparametric Tests – One Sample SPSS Kolmogorov-Smirnov Test for […]
