The phenomena social psychology seeks to explain--how people think, feel, and act in response to social situations--are rich and diverse. Therefore, explanatory power, the simplicity of a model relative to its empirical scope, is an important desideratum for social psychological theories. A model achieves high explanatory power to the extent that it integrates narrower models within a unified conceptualization, reconciles conflicting findings, and makes novel predictions regarding specific phenomena. This article first relates explanatory power to the various facets of scientific inquiry (modeling, derivation, observation, evaluation, and decision) and then discusses this criterion as a guide for 2 theory-based lines of research my colleagues and I have conducted in the area of social judgment and decision making.