There is one further characteristic of a PBL environment that helps to create an authentic context for learning, and that is its complexity. Real-world problems are usually complex, hinging on the interrelationships of numerous details and perspectives. The intention might be to ease the cognitive demands placed on the learner, but the effect is to decontextualize learning, making it more difficult for learners to understand the purpose or applications of the knowledge being presented. In problem-based learning, students begin with a problem to solve, then proceed to identify the issues they need to know about in order to understand and solve the problem. In other words, the content studied is determined by the students, and their selection is based on what they believe will be most useful in the task at hand, that is, solving the problem.
Students practice self-direction in their group interactions as well.
Working either in small groups or as a class, students must decide how to divide up the responsibility to find and learn information. They must also choose their own path to the solution by determining their own sequence of steps through the process and strategies they, as a group, will employ. Cooperative learning can benefit PBL in a number of ways. By assigning these roles to different students, the types of thinking involved in problem-solving are differentiated, externalized, and made explicit. Students have the opportunity to practice one role at a time, then switch and practice another.