ABSTRACT

Before the PBL exercise can be implemented, the instructor must formulate the problem. A good problem is one that changes the more the student learns about it. It is ill-structured, in contrast to well-structured problems and puzzle problems. For example, a well-structured problem requires “the application of a finite number of concepts, rules, and principles being studied to a constrained problem situation” (Jonassen 1997, 65-95). These problems are also called transformation problems (Greeno 1978, 239-70). These problems offer the student a well-defined initial condition, a known goal, and a limited set of logical operations. These are the most commonly encountered problems in textbooks. The student encounters them as an orderly and finite domain of knowledge. Everything needed to solve the problem is in the book. A puzzle problem is a well-structured problem with a single correct answer where all the elements required for the solution are known, no background knowledge is required (i.e., the information on the preceding pages of the textbook is all that is relevant), and the solution requires using logical, algorithmic processes (Kitchener 1983, 222-32). In an ill-structured problem, on the other hand, the solution is “the object of ongoing controversy, even among qualified experts” (Wood et al. 2002, 277-94). Ill-structured problems are situated in and emerge from a specific context, but one or more aspects of the problem situation are not well specified, the problem descriptions are not clear or well defined, or the information needed to solve them is not contained in the problem statement (Chi and Glaser 1985).