ABSTRACT

Some seventy years ago, Karl Duncker (1945) produced a useful definition of a problem situation as one in which a person has a goal but does not know how to reach that goal. Problems come in many guises but can be classified in various ways. One classification is into those in which all the elements of the problem – the starting situation or state, the goal state and the means available for moving from the starting state to the goal, – are well defined as against problems where some or all elements are ill defined (Reitman, 1964; Simon, 1977; Lynch, Ashley, Alevan & Pinkwart, 2006). A chess problem is a prototypical example of a well-defined problem, in which the starting state is given, the goal is well defined (say, checkmate for white in three moves) and the means available are specified by the legal moves in the game. On the other hand, a problem may be very ill-defined, such as that of “improving the quality of life”, in which the starting state, the goal state and the means available are not well defined. In ill-defined problems, it seems likely that an initial step is generally to convert the problem into a better-defined one by specifying some of the missing information (Weisberg, 2006, p. 139). In the “improve the quality of life” problem, some of the missing information could be specified by deciding on a particular way of measuring quality of life such as using the World Health Organization Quality of Life (WHO-QOL) questionnaire (WHO-QOL group, 1995) which would help determine the starting state and could be used to assess any effects of interventions as strong or weak.