We have restored our quantile-quantile tutorial from our previous site and is now available at


This is an Excel-based tutorial.

10-18:2016 Update: As of 10-18-2016 we are providing a link to an Excel .xlsx file that reproduces Table 1 of the tutorial.

Quantile analysis by means of constructing quantile-quantile plots (q-q plots) is a technique for determining if different data sets originate from populations with a common distribution.

If the common distribution is normally distributed, a q-q plot can be used to test for normality. The technique is applicable to a wide range of data mining and engineering problem.