In the last lesson we saw that we can view AI from a philosophical perspective by considering whether machines can really possess intelligence or not. While we certainly will not be able to answer that question in this lesson, we can stimulate some more thought by comparing the human mind to the current computer technology. The following animation compares the storage capacity and processing speed of the brain to that of the fastest computers currently available. The estimates for this comparison were taken from The Analytical Engine by Rick Decker and Stuart Hirshfield [1998].

When comparing the processing capabilities of the human mind and the computer, it is important to remember that each one is good at certain tasks. While computers can crunch long lists of numbers in milliseconds, humans can decide what the results mean and what action should be done based on those results. Computers are good at computation with numbers while humans are good at reasoning and interpretation.

To demonstrate this difference, let's run an experiment that will pit you against the computer in two different tasks that involve artificial intelligence. The first task is playing a game of checkers. Since this task can actually be reduced to number crunching, computers are quite good at it. In fact, the world champion checkers player is currently a computer. Try playing a game of checkers [Fabio 1997] against your computer in the applet below and see how well you do.

The second task in our experiment is carrying on a conversation. This is the type of task at which humans are good and computers are poor. Conversations can not be reduced to simple number crunching, so computers can not perform nearly as well at this task. Typical conversations involve a huge amount of "world knowledge" or common facts about life which humans accumulate as they grow. Remember in our animation we saw that humans have a 50 to 1 advantage in terms of information storage. What seems to be effortless for us is quite challenging for a computer.

The applet below is a version of a program called ELIZA which was first developed by Joseph Weizenbaum in the mid-1960s. The program as designed to imitate the role of a psychologist asking questions to a patient. Try starting a conversation with ELIZA [Goerlich 1996] and see what you think of your computer's ability to talk.

At the least, our experiment in this lesson has confirmed the basic observations we made about AI, namely, computer intelligence is currently limited to tasks that are easily reduced to algorithms and number crunching. Remember, however, that the goal of AI is "to develop more powerful, versatile programs that can handle problems currently handled efficiently only by the human mind." In the next few lessons we will look at some applications that are trying to use computer intelligence to support tasks traditionally handled by humans.