The main conclusions are on the field of problem solving methods, how reusable components have to be learned and how to stimulate creativity. They are described in this section.
Depending on the understanding of the description of the problem (ie. requirements) and the familiarity with the reusable components, there exist three kinds of obstacles for finding a solution. The three kinds are: interpolation problem, dialectic problem, and synthesis problem [4]. An interpolation problem occurs when the combination of a good understanding of the problem and the components happens. A dialectic problem occurs when the combination of a good understanding of the components and a low understanding of the problem happens. A synthesis problem occurs when the combination of a bad understanding of the components and a high understanding of the problem happens. A combination of dialectic and synthesis problem exist in case of a low understanding of the problem and of the components. The problem solving methods which one has to follow depending on the kind of obstacle are described in [4]. General problem solving methods are described in [16,17,25].
Two kinds of learning of components can be of importance for the reuser. The first kind of learning is the acquisition of broad, non-specific, general notions about the properties of the component experienced. This seems to provide the knowledge repertoire essential for productive (∼creative) thinking. The second kind of learning is the acquisition of experiences which provides perceptions of specific, limited, functional characteristics. This seems to lead to ``functional fixedness'' in problem solving perceptions. Such fixedness limits the range of perceptual organisations capable of being developed by the reuser and so interferes with problem solving [3].
It is clear that the functional fixedness kind of learning is of little use for a reuser, but it is of use for a problem solver who only solves one kind of problems. The discrepancy between usefulness and uselessness of functional fixedness can be overcome by learning basic specific facts coupled with general problem solving techniques. In [11] it is advised to learn first the global concepts used by the component before the mechanics.
The main difference for problem solving with and without existing components was lain in the fact that components could be seen as giving a hint as in which direction to look for a solution.
The solving of problems asks for creativity. By accepting the idea that the long term memory is associative [26] and that knowledge in the long term memory is clustered into schemata [12] and that the retrieval of knowledge from the long term memory is keyword-based [26] we can sketch an approach for being creative [26]. The memory has to be prepared to meet the conditions required for creativity. By storing a lot of questions in the memory answers will be recognised when they come along. Thus during the process of learning one has to ask oneself all the ``w''-questions, why, when, where, etc. One also has to try to relate new information to the own schemata [26]. If a rich store of novel integrative schemata and unanswered questions exists in memory, and if good cognitive plans for playing with ideas exist, ideas can be created on demand much as any other skill can be performed [26].