The Structure of Ill-Structured (and Well-Structured) Problems Revisited

In his 1973 article The Structure of ill structured problems, Herbert Simon proposed that solving ill-structured problems could be modeled within the same information-processing framework developed for solving well-structured problems. This claim is reexamined within the context of over 40 years of subsequent research and theoretical development. Well-structured (puzzle) problems can be represented by a problem space consisting of well-defined initial and goal states that are connected by legal moves. In contrast, the initial, goal, and intermediate states of ill-structured (design) problems are incompletely specified. This article analyzes the similarities and differences among puzzles, insight puzzles, classroom problems, and design problems within Gick's (Educational Psychologist, 21, 99–120, 1986) theoretical framework consisting of representation construction, schema activation, and heuristic search. The analysis supports Simon's (Artificial Intelligence, 4, 181–201, 1973) claim that information-processing principles apply to all problems but apply differently as problems become more ill structured.