Thinking can be categorized into reasoning and problem solving. Although these are not distinct they are helpful in clarifying the processes involved.
If it is raining then the ground is dry.
It is raining.
Therefore the ground is dry.
is a perfectly valid deduction ! Deductive reasoning is therefore often misapplied. Human deduction is at its poorest when truth and validity clash. This is because people bring their knowledge of the real world into the reasoning process as it allows them to takeshort cuts which make information processing more efficient.
Abduction reasons from a fact to the action that caused it. This is the method we use to derive explanations for the events we observe. This kind of reasoning, although useful, can lead to unreliability as an action preceding an event can be wrongly attributed as the cause of the event.
Problem solving is the process of finding a solution to an unfamiliar task, using the knowledge we have. There are a number of different views of how people solve problems. We shall consider two of the more recent and influential views: Gestalt theory and the problem space theory.
Gestalt theory claims that problem solving is productive and reproductive. Reproductive problem solving draws on previous experiences whereas productive problem solving involves insight and restructuring of the problem. Reproductive problem solving could be a hindrance to finding a solution, since a person may fixate on the known aspects of a problem and so be unable to see novel interpretations that might lead to a solution.
A well known example of this is Maier's `pendulum problem'. The problem was to tie together pieces of string hanging from the ceiling. However , they were far too apart to catch hold of both at once. The room was full of other objects including pliers, poles and extensions. Although various solutions were proposed by participants, few chose to use the weight of the pliers as a pendulum to swing the strings together. However, when the experimenter brushed against the string, setting it in motion, a lot of participants came up with the idea. This can be interpreted as an example of productive restructuring. This experiment also illustrates fixation: participants were unable to see any meothd beyond the use of a pair of pliers.
However, Gestalt theory does not provide sufficient evidence or structure to support its theories.
For example, imagine you are reorganizing your office and you want to move the desk from one end to another. The two different states are represented by the locations of the desk. A number of operators can be applied to move these things: they can be carried, pushed, dragged etc. In order to ease the transition between the states, you have a new sub-goal: to make the desk light. These may involve operators such as removing drawers and so on.
Within the problem space framework, experience allows us to solve problems more easily sice we can structure the problem space appropriately and choose operators efficiently.
People solve novel problems by mapping knowledge in a similar known domain, to it. For instance, to destroy malignant tumour it is essential to fire low intensity rays from all sides, as high intensity rays can damage heathy tissues. An analogous case is that of attacking a fortress. However, people miss analogous information unless it is semantically close to the problem domain.
Skills in a given problem area differentiate the novice from the expert. A commonly studied domain is chess playing. It is particularly suitable since it lends itself to representation in terms of problem space thoery, in which the intial board configuration and the final position constitute the states while the moves appeared as transition operators. Masters took lesser time than novices to react to a situtation and produced better moves. This is largely because chess masters remember board configurations and good moves associated with them. They can chunk the board configuration in order to hold it in short-term memory.
Skilled behavior becomes automatic over a period of time. Experts tend to mentally rehearse their actions in order to identify exactly what they do. Althoug such skilled behavior is efficient it may cause errors when the context of the activity changes.
