# Is it possible (or even usefull) to transform Log transformed data into Z-scores?

We have created a questionnaire. In this questionnaire there are different dimensions with different answering scales.

Because of our rightly skewed data we log transformed our data. But here is the thing:

Because of the different answering scales (some are Likert 5, some Likert 7, and even a dichotomous scale) they have suggested to transform our data into z-scores. This would be applicable if the data wasn't log transformed, but is it usefull (possible) to transform the log transformed scores into z-scores?

P.s.) We eventually want to perform a Bivariate Correlation and Linear regression (with SPSS 16).

However, both bivariate correlation and linear regression will ignore your transformation. This is because Pearson correlation coefficient ($\frac{cov(X,Y)}{\sqrt{var(X)var(Y)}}$) and prediction of pure OLS linear regression ($X(X^TX)^{-1}X^TY$) will not change if you multiply $X$ by a constant. So for these purposes you don't need z-transformation.