Usefulness of the Z score - Essay Example

Usefulness of the Z score Statistical data has various characteristics which makes it keep deviating, depending on the statistical tools of analysis that are applied to condense and interpret the data. This being the case, there is a need to have a common yard stick that provides the standardization of such variant data, to give a common statistical result, and thus help the statisticians or the researchers easily and meaningfully interpret and make data inferences. Z-score acts as the common yard that helps to standardize the standard deviation that is observable in data, to arrive at an indication regarding how many standard deviations a certain data is above or below the mean.

Through understanding how far or close data is from the mean, it is possible to assess its deviation from the normal distribution. A high deviation of a certain data from the standard normal distribution is an indication that the score obtained in an aspect in question is further from the mean score, while a small deviation indicates that the score is very close to the mean value of the data. The usefulness of a Z score is that it enables statisticians to calculate the probability of any score occurring within the normal distribution.

Additionally, a Z score is useful in enabling statisticians and researchers to compare two values or scores that are obtained from two different normal distributions. This standardization of two scores can indicate that while an individual has scored relatively highly in a certain aspect, he/she may not have attained the highest score obtainable in that aspect.