Occam's Razor is a logical principle that is used in all sorts of research and modeling situations. It is used by social scientists when they are trying to create models to explain results that are observed in the real world.
Occam's Razor holds that when you are trying to explain something, you should use the simplest possible explanation for that thing. If you have two possible explanations, you should use the simpler one.
This is particularly important in social sciences where scholars have to look at results that could have been caused by a number of factors. They have to build models to explain those results. Occam's Razor tells them to try to make their models as simple as possible rather than making them complicated.