There are many possible examples of empirical reasoning in the social sciences. Basically, any time that you try to determine truth through looking at (and trying to quantify) conditions in the world, you are engaging in empirical reasoning.
Therefore, empirical reasoning can take many forms. In political science, you can try to draw connections between the "safeness" of a politician's seat (the average margin of victory for their party) and the way the politician votes (how often they vote with the majority of their party). In sociology, you can try to find the correlation between level of education and level of criminal activity. These things can be relatively easily quantified and therefore will appear to produce truth about the world through observation and quantification.