How do I transform variables?
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Revision as of 20:54, 7 September 2009 by Doug
- How do I transform variables?
- There are different types of transformations based upon the type of non-normality. So the first step is to identify the type of non-normality, and then identify which transformation is used for that type of non-normality. The Tabachnick & Fidell book "Using Multivariate Statistics" in section 4.16 (pp. 82-82) provides detailed information about each type of non-normality and the corresponding mathematical transformation.
- The second step is to use statistical software to create the newly transformed variable using the appropriate mathematical formula, such as using the "Compute" function in SPSS.
- The final step is to check the normality of the newly created variable. See How do I determine whether my data are normal? If the variable is normal, then you can start conducting statistical analyses using that variable. If the variable is still non-normal, then try other related transformations.
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