CMSC 671, Fall 2010
Prof. Marie desJardins

HOMEWORK ONE
out 9/8, due 9/22

Problem 1 (10 points)

Russell & Norvig, exercise 3.12 (page 115).

Problem 2 (15 points)

Russell & Norvig, exercise 3.15, (a)-(d) (page 116)

Problem 3 (75 points)

Adapted from an assignment prepared by Dr. Tim Finin

This is a simple exercise to help you think about the question of how one could decide if a machine was "intelligent" or not.

Turing Test

"The Turing test is a behavioral approach to determining whether or not a system is intelligent. It was originally proposed by mathematician Alan Turing, one of the founding figures in computing. Turing argued in a 1950 paper that conversation was the key to judging intelligence. In the Turing test, a judge has conversations (via teletype) with two systems, one human, the other a machine. The conversations can be about anything, and proceed for a set period of time (e.g., an hour). If, at the end of this time, the judge cannot distinguish the machine from the human on the basis of the conversation, then Turing argued that we would have to say that the machine was intelligent.

There are a number of different views about the utility of the Turing test in cognitive science. Some researchers argue that it is the benchmark test of what Searle calls strong AI, and as a result is crucial to defining intelligence. Other researchers take the position that the Turing test is too weak to be useful in this way, because many different systems can generate correct behaviors for incorrect (i.e., unintelligent) reasons. Famous examples of this are Weizenbaum's ELIZA program and Colby's PARRY program. Indeed, the general acceptance of ELIZA as being "intelligent" so appalled Weizenbaum that he withdrew from mainstream AI research, which he attacked in his landmark 1976 book." (From The University of Alberta's Cognitive Science Dictionary)

Try it Out

Experiment with one or two programs that offer an interface that appears to understand unrestricted natural language input. Here are a couple of programs that you can try:

Assignment

  1. Start by reading Turing's original paper (Turing, A.M. (1950). Computing machinery and intelligence. Mind, 59, 433-560 (pdf) and John McCarthy's essay, What is Artificial Intelligence. Then explore the Loebner Prize web site. (Note -- Hugh Loebner was director of UMBC's academic computing services department in the 80's).
  2. The Turing Test allows an unlimited range of questioning and is thus a very difficult proposition. The Loebner prize version of the Turing test is much more limited -- in topic and in duration and offers computer programs a much better chance of passing. Speculate on whether such a "partial" Turing Test makes sense. Explain your ideas in an essay of 400-600 words. Would it be a worthwhile effort? What does it tell us about the nature of understanding natural language conversations? What possible problems could arise?
  3. Choose one of the papers from the following list: Write a 200-400 word summary of the main points in your chosen paper.

Additional Background Reading