Why would you want to transform a set of raw scores into a set of z-scores? When you transform raw scores into a set of z-scores, you are able to compare the scores from both distributions. When you compare the scores, you can allow one to have a mean of 0 and a SD of 1. A raw score is a score that has not been changed or altered in any way. A z-score lets us see how many standard deviations away from the mean an element lies.
