Introduction to Cognitive Science
Minimax Exercise
Project Description
Due: Tuesday, Dec. 1
Please complete all parts listed below. The goal of this
exercise is to give you experience with configuring the features of a
heuristic for the game connect-4. After completing it, you should
have a better understanding for how a heuristic encodes
knowledge about playing a game, how important it is for
computer game playing, and hopefully gain some insight into how humans
(in particular, you) play games.
- There is a sample game board, representing an intermediate state
of a game of connect-4, at the bottom of this page. Generate a
complete game tree for a two-ply search (i.e. all possible states two
moves after the one shown).
- Play connect-4 against the computer. The game page can be accessed by
clicking here.
- For each game you play, record the feature weights you have chosen and
the sequence of moves you have made. In your first game, keep all the
feature weights at zero. It should be pretty easy to win. Notice
that the computer, for the same set of weights, always responds in the
same way to the same set of moves. This particular game playing
system is deterministic, but you should be aware that many
symbolic game-playing systems are not, and will in fact respond
differently to the same sets of moves.
- For your second game, look at the features and assign some
weights to them. Note that if you assign weights to every feature,
the computer will take a long time to make each move, especially at
the beginning of the game. Therefore you should try only a few
features at first.
- Whenever you lose a game, try playing again with the same
weights. Since you should have recorded all your moves, try to
analyze mistakes you made and vary your own moves to try to win.
- Whenever you win a game, try and determine a new set of weights
that will make the computer better.
- Keep playing until you have developed a fairly good set of
feature weights.
- Hand in your record of features and moves. Indicate which set
of features you feel is the best and why.
- Comment on how playing the game increased your own skill over
time. You don't have to go too deep, focus in particular on any
features that you found yourself using.
- Finally, try to think of another feature that, if added to this
heuristic, would make this system play better.
Red moves next.
