The Kruskal-Wallis test is a non-parametric statistical test used to compare three or more independent groups. Unlike parametric tests like ANOVA or t-tests, it does not assume normal distribution of the data. Instead, it ranks the data and compares the mean ranks between the groups.
Key Characteristics:
- It is an extension of the Mann–Whitney U test to more than two groups.
- Useful when data is ordinal or not normally distributed.
- It compares medians rather than means.
Analysis of Other Options:
- (a) ANOVA: Assumes data is normally distributed and groups have equal variances.
- (b) Student T test: A parametric test that compares means and assumes normality.
- (c) Fisher LSD test: A post-hoc test following ANOVA, also assumes normal distribution.