Levene’s test checks the homogeneity of variance assumption, not the normality assumption.
If Levene’s test shows that your data violates the homogeneity of variance assumption, then you have the following choices:
– make sure that the homogeneity of variance assumption isn’t being being violated because of outliers; if so you need to deal with the outliers first
– perform a one-way analysis instead using Brown-Forsythe or Welch’s test, which do not require homogeneity of variances
– transform the data to try to eliminate the problem. Typical transformations are log(x), x^2, 1/x
I really enjoyed your threads and am amazed with the way you explain things that is understandable even to a beginner like me. Came across your website by accident while looking for chi-square vs logistic regression explanations. Thank you! A quick question: The place where I work is currently using a tool to categorize feeding difficulties in children and it has never been validated. BUT it has been widely used world wide (~8 countries) with studies proving its efficacy. Is it feasible to make a research using this tool without going through a validation study? Thanks very much !