Problem Solving

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

2. 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.

3. 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.”

4. 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.

5. 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.