Evaluation Function

• We had an evaluation function in the genetic algorithms lecture.
• This is the same thing.
• How do you evaluate a final tic-tac-toe board?
• How do you evaluate a final chess board?
• How do you evaluate an intermediate chess board?
• How do you evaluate go boards?
• Typically, you don't have the final answer, so you have to have a heuristic result.
• So with tic-tac-toe, you can tell if a certain move may lead to a loss, or will lead to a win.
• But with chess, you can't look enough moves ahead (except toward the end of a game).
• This means the evaluation function is heuristic.
• It typically returns a value (an integer will do).
• You can learn the evaluation function, see Samuel's Checkers Player.