The Future of Artificial Intelligence

John Paxton

Montana State University

August 14, 2003

Bannack

What makes AI difficult?

• Different problems have inherently different complexities to solve.

The Sorting Problem

• Input: 2 4 6 7 5 3 1

• Output: 1 2 3 4 5 6 7

Selection Sort

• Step 1: 2 4 6 7 5 3 1

• Step 2: 2 4 6 1 5 3 7

• Step 3: 2 4 3 1 5 6 7

• Step 4: 2 4 3 1 5 6 7

• Step 5: 2 1 3 4 5 6 7

• Step 6: 2 1 3 4 5 6 7

• Step 7: 1 2 3 4 5 6 7

Selection Sort

• If there are n items to sort, selection sort takes O(n2) time

• What does this mean? If we double the size of the input, we can expect the algorithm to take four times as long.

Quicksort

• O(n log2 n)

2 4 6 7 5 3 1

1 4 6 7 5 3

3 6 7 5

5 7

Quicksort

n n log2 n n2

10 33.22 100

100 66.44 10000

1000 99.66 1,000,000

10000 132.88 100,000,000

Sorting

• It can be proven that sorting n numbers based on comparisons has a best case of O(n log n).

• Thus, the inherent complexity of sorting is O(n log n), even though worse algorithms such as selection sort exist.

The Class P

• P = Polynomial

• Any problem whose inherent complexity is O(np) where p is a constant is in the class P.

• Problems that are in P typically are practical to solve on computers.

Travelling Salesperson Problem

• Starting in City A, what is the shortest circuit that visits cities B, C, and D?

• A – B – C – D – A• A – B – D – C – A• A – C – B – D – A• A – C – D – B – A• A – D – B – C – A• A – D – C – B - A

TSP

• In the preceding problem, there were 4 cities and 3! possible solutions

• In general, if there are n cities, one must consider (n-1)! possibilities.

• (n-1)! is not O(np) for any fixed p. (n-1)! is in the EXP class.

• Each problem in the EXP class is O(pn) for some fixed p.

Comparison

n n2 (n-1)!

5 25 24

10 100 362,880

15 225 8.7E10

20 400 1.2E17

The Class EXP

• As you can see from the preceding table, problems that are in the class EXP do not have practical solutions on computers

Relevance to AI

• Unfortunately, many interesting problems in AI are in the class EXP.

• For example, the TSP problem.

Satisficing

• What can be done?

• Instead of settling for the optimal answer, look for a “pretty good” solution instead. This technique is also known as satisficing.

Satisficing Example

Heuristics

• A “heuristic” is a rule-of-thumb that works in practice, but has no guarantee of being optimal.

Water Jug Problem

• Place 6 liters of water in the 8 gallon jug in as few steps as possible

8 3

Water Jug Problem

• Place 8 liters of water in the 10 gallon jug in as few steps as possible

10 4

Water Jug Problem

• Place 10 liters of water in the 15 gallon jug in as few steps as possible

15 5

Past AI Predictions

• Game Playing. Researchers thought that AI chess playing programs would beat the best humans by 1970.

• Machine Translation.– The spirit is willing, but the flesh is weak.– The whisky is strong, but the meat is rotten.

Objections to AI

• Theology• Heads-in-the-Sand• Mathematical• Self Awareness• Capability X is lacking (e.g. enjoy ice cream)• Lady Lovelace’s objection• Continuity of nervous system• Informality of behavior (no rules)• ESP

The Future

• Consumer Robots

The Future

• Gastrobots (University of South Florida)

• Sustain themselves by eating naturally occurring foods

The Future

• COG, a robot at MIT

• Track eye movement• Recognize faces• Grab objects• Hear a rhythm, play it

back on drums

The Future

• Art – Raymond Kurzweil’s screensaver program, Aaron

• Poetry

• Music

The Future

• Natural Language

• Charles Schwab incorporates iPhrase at its web site to allow users to use natural language to ask questions. For example, “Which of these stocks has the highest revenues?”

The Future

• Products that do one thing well.

• For example, Continental Divide Robotics has developed a system based on GPS that can locate any person or any object anywhere in the world and notify a user if it is “out of bounds”. This could help a parent monitor a child, for example.

The Future

• Companionship

• At Microsoft, a product is under development that learns about you. Who is important to you? Are you busy? The product can then monitor incoming e-mails and phone calls.

The Future• Virtual Reality

• Haptek, People Putty

• Create your own 3-D interactive characters

The Future

• Computers will get faster

• Software will get better

• AI will creep closer to human capabilities (search, learning, knowledge representation)

The Future

• There are lots of potential benefits!

• There are certainly some potential drawbacks!

• Most AI researchers believe humans will stay in control

Questions?