For observational data does the Anova requires nonrandom or

For observational data, does the Anova requires non-random or random sampling??

To perform ANOVA, the researcher assumes the following: For each population, the response variable has a normal distribution, the variance of the response variable is the same for all populations and the observations are independent of each other . The assumption of independence may be satisfied in an experimental study with randomized design or in an observational study with sampling. In ANOVA, the F-test statistic is the ratio of the between-treatments and the within-treatments estimates of the population variance sigma^2. When the null hypothesis is true, both the between-treatments and within-treatments estimates of sigma^2 the population variance, so the F-test statistic is

Solution

Any test requires random sampling.

Hence, for ANOVA as well, it requires RANDOM SAMPLING here. [ANSWER]