How is sociology (and the sociological imagination) different from just sitting on a bench and people watching all day?

Karl Marx, Emile Durkheim, Max Weber, and Auguste Comte were four of the individuals responsible for the early development of sociology. Write about the major contributions ONE of these great thinkers made to the science of sociology. 
Develop an essay that explains the development of sociology, those individuals responsible for its early development (examining briefly the contributions these people made to sociology), and the accepted definition of sociology today. 
How is sociology (and the sociological imagination) different from just sitting on a bench and people watching all day?
What is a theory? Why are theories necessary in sociology? What is the relationship between theory and fact?
Discuss at least three ways sociology can make a difference in your world.