It is useful to recall that our work as scientists will be at its best when it simultaneously tackles real-world problems and enriches our understanding of basic biological, psychological, or social processes. A good theory can help us do both. All empirical research is based on assumptions. Even purely “descriptive” or “exploratory” studies necessarily involve choices about the phenomena and variables to observe and the level of detail at which to observe them. Researchers planning an empirical study confront the challenges of making these assumptions explicit, examining them critically, and designing the investigation to yield data that permit those assumptions to be evaluated and modified appropriately. This is the process of theory construction. Unfortunately, although all research is based on theory, many grant proposals lack a well-developed theoretical rationale. The theoretical framework often remains implicit in the proposal without being formally articulated. Consequently, even though the application may be based on a good idea, it is conceptually weak and receives a poor priority/impact score. This chapter will give you a useful strategy for developing a clearly articulated theoretical framework for your research project and using it to write your entire research plan.