Policy process research is the study of interactions among people and public policy. Policy process research is often depicted by the policy cycle. The policy cycle refers to the key stages of policymaking: (i) how people struggle to define issues as problems worthy of attention on government agendas; (ii) how people analyze problems and devise and select among policy alternatives; (iii) how people implement policy; and (iv) how people evaluate and sometimes terminate policy. Also called the stages heuristic (Sabatier, 1999), the policy cycle began in the original work by Harold D. Lasswell (1948/2009; 1956) and later refined by others, notably Brewer (1974), Brewer and deLeon (1983), and deLeon (1988). In many ways, the policy cycle has defined public policy research, more as a typology, however, rather than as an analytic framework (deLeon, 1999). Among the leading textbooks in public policy, James Anderson (2005), Howlett and Ramesh (1995), and Kraft and Furlong (2007) portray policy process research by the policy cycle.
The policy cycle, however, too narrowly depicts the scope of policy process research. A cursory look at the theoretical and practical applications of policy process research shows that it encompasses, at a minimum, the study of (i) political behavior among individuals, groups, and coalitions; (ii) minor and major policy change; (iii) the role of experts and citizens as well as the different uses of information and other resources; (iv) collective action problems as related to public policy issues; (v) social constructions; and (vi) power, inequalities, and policy designs. Depictions of policy process research that transcend the policy cycle can be found in the theories, frameworks, and models in Sabatier’s edited volume (2007) and in the introductory primers by Parsons (1995), Birkland (2001), and Smith and Larimer (2009).
Lasswell famously argued for policy research (i.e., in his case, the policy sciences) as a function of “knowledge in” and “knowledge of” the policy process (Lasswell, 1971). The Policy Process Research Lab intentionally focuses on Lasswell’s “knowledge of” description, which largely reflects our above description of policy process research. The “knowledge in” description is the traditional practice found in policy analysis and evaluation literature (e.g., the work associated with Weimer and Vining  or Stokey and Zeckhauser). The traditional differences between the policy process and policy analysis/evaluation literatures are several, with the latter usually designed to place low emphasis on theory and high emphasis on improving democracy, conducted in service of a client, and published as practitioner reports.
Trying to understand and explain the policy process requires an understanding of the relationships among a complex number of factors in dynamic systems with nested levels of interactions and uncertain inputs and outputs. In the policy process, hundreds of government officials and people outside of government with different beliefs and interests interact, and their interactions are embedded in a community with its own history, geography, and formal and informal institutions. Given the enduring truth that people’s cognitive limitations fundamentally constrain their ability to observe the world, the question then emerges: How can we possibly make sense of a complex, often interactive phenomena and their effects on the public policy?
One of the best strategies for approaching complex phenomena is to employ frameworks, theories, or models that can help organize or explain this complexity. However, any singular framework, theory, or model will fail to capture the full range of factors that shape or underlie policy processes. Thus, policy process researchers must understand and be able to apply the diverse analytical approaches that are available to them to have a comprehensive perspective on policy processes. In this sense, then, the conditions imposed by the problem will motivate the approach employed.