What about cases where we have two groups and we want to see if the two groups differ but the data is not normally distributed? In that case we can use one of two non-parametric tests. The first is called the Mann-Whitney U Test and test to see whether two groups are different when each group is made up of different people.
Note: If you are using version 18 of SPSS (also known as PASW 18) there are now two ways of conducting non-parametric tests. To follow the instructions shown in the video follow the same menu selection of Analyse -> Non-parametric Tests and then goto Legacy Dialogs. This will bring up the same menu that you see in the videp.