Problem Solving How do people solve problems? What factors influence the ways they solve different types of problems?

Problem Representation What kinds of information do we need to know in order to solve a problem? –Problem states: The status of all the various elements of a problem. –Operators: The valid ways you can manipulate the elements of a problem; also called the legal moves.

The Problem Space The problem space is the collection of all of the possible problem states and the operators that connect them. All problem spaces have at least two states: –Start state: The initial state of the problem –Goal state: The state you need to be in to deem the problem as “solved.”

What problem solving is. Problem solving is, psychologically, the process of finding a path through the problem space from the start state to the goal state. This path can only utilize legal operators to travel from one state to another. The study of problem solving today is the study of how people find this path.

Problem solving strategies Generate-and-test: a.k.a trial and error Working forward: Start at the start state and use operators that seem to be moving closer to the goal state. Working backwards: Start at the goal state and use the operators in reverse to move backwards to the start state. Hill climbing: Always use an operator that appears to take the largest step towards the goal state. Means-ends Analysis: Always take steps that reduce the distance between the current state and the goal state.