Using competition to motivate students: an AI assignment case study

Andrew WilliamsGames Team LeaderA.Williams@bolton.ac.uk

Index

1. Games at Bolton2. Hexapawn assignment in AI3. The role of competition4. Future directions5. Questions

Games at Bolton

Games at Bolton Three dedicated members of staff

About a dozen others contribute 138 current students

55 first years Sixteen graduates so far

Two dedicated games labs 25 PCs each Including PlayStation NetYaroze and PS2

Linux Consoles

Games at Bolton

Two courses: Computer Games Software Development

Very technical Now in its fourth year

Games Design More creative and less technical First recruitment September 2005

Games at Bolton

Sixteen students have graduated from the CGSD course so far Four are working for a local games

company One has devised and delivered games

courses for teenagers One has set up his own company

producing educational games Several teams working on “mods”

Hexapawn Assignment in AI

Why I’m not boring (*)

Chiefly because of my chess program Started in 1998 Equal 5th in first Computer Chess

Tournament (CCT1), February 2000 15th in World Computer Chess

Championships, Maastricht 2002 8th in first CCT-BLITZ tournament,

October 2005

* According to my boss

The AI module A level 3 module

Optional All games students do introductory AI

elsewhere in their studies Offered to students from other

programmes Usually taught by two people in tandem,

each covers topics that he finds interesting I like 2 person, perfect information games

Two person, perfect information games

Chess Draughts Noughts and

Crosses Hexapawn

Hexapawn rules: White goes first Pawns move one square

forward… … or they can capture

diagonally Win if your pawn reaches the end Lose if you have no moves (or no

pawns)

Choosing hexapawn

Hexapawn is more interesting than OXO in terms of game-tree search Expand the board Change piece behaviour

Small-sided game still too easy

Thought experiments: Who wins if White starts with b1-b2? Who wins if White starts with a1-a2?

1

2

3

a b c

If I do this and he does that…

1

2

3

a b c* a1-a2 is left as an exercise

Starting with b1-b2 b1-b2 a3xb2 c1xb2 c3-c2 a1-a2 c2-c1 And we reach the position below

Black has reached White's back rank (on c1), so Black wins

A new game with new rules 8x8 board 16 pieces each Double first move

from the back rank Over four weeks

we developed a simple program in C for playing hexapawn

The “hexapawn” assignment The assignment was to improve the

program in certain ways: Better evaluation Better game-tree search

Students could swap object files to test against each other without revealing their techniques

30% awarded for performance in a tournament (20% for trying interesting things, 50% for report and documentation)

The Role of Competition

My kind of assignment

Essentially, the assignment is a miniature version of what we do in the world of computer chess Difficult Frustrating Easy to judge progress Fun Rewards thorough testing

Results The assignment has been conducted twice

with twelve students in total Average score of 60% Several students have commented

favourably on the assignment Several exchanged versions over Christmas

so that they could assess their progress One student complained that he spent so

long on hexapawn that he neglected other work

Results

A wide range of techniques were implemented Player on move is critical Null move doesn’t seem to work well

Contrast with chess, where null move is key Hash tables are a major win

Predictably hard to get working It turns out that leaving defenders back

is a very good strategy

Results All students managed to produce a

version that could beat the bog-standard williams program I had expected this

One student produced a version that consistently beat my best version I had not imagined that this could

happen! It had never occurred to me to leave

defenders back

Future Directions

Time to put hexapawn away?

The structure of courses in our department has changed

Probably from next year, only games students will study AI

Replace hexapawn with something more like a video game But retain the element of competition as

a motivating tool

Any Questions?