Idealized decision theory tells us how we ought to choose our actions, but its instructions are highly abstract. While the theory is framed in terms of acts, states, and outcomes, we can often gain more clarity about practical ethical decisions by thinking in terms of problems, interventions, and focus areas.
A problem is something that is currently true about the world, which, if it stopped being true, would make the world a better place. “Many people die each year from malaria” is an example of a problem.
Interventions are methods for solving or making progress on problems. Bednet distribution is an example of an intervention, which is meant to address this problem.
In addition, although this concept is somewhat vaguer, we can define focus areas as fields around problems or sets of closely related problems. Global poverty is an example of a focus area.
Note that introducing these additional concepts does not prevent us from using decision theory to guide our actions. For example, we might ask, “What would be the value of an outcome in which this problem is solved?” or “What is the expected value of a donation to a charity that carries out this intervention?”