Experimental psychology uses the scientific method to establish causal correlations through experiments, as opposed to theories. Experimental psychology works toward a specific question, like, "Do electrical currents excite nerves in the legs?" as opposed to larger questions like, "What is consciousness?"
Experimental psychology differs from the more theoretical branches of psychology, such as psychoanalysis. Whereas experimental psychology begins with a hypothesis about a phenomena and tests it through predictive experimentation, psychoanalysis begins with a theory about how a phenomena works, or observes a phenomena and constructs a theory. Experimental psychology requires stringent, peer-reviewed case studies and experimental analysis, whereas psychoanalysis requires logical coherence and consistency without technical, experimental data.