Download AI from the Perspective of Cognitive Science

AI from the Perspective of Cognitive Science
Study Questions for Meetings #4 and #5
Knowledge Representation
Stillings et al., Chapter 4 (“Knowledge Representation”)
1. (p. 139) What are some advantages of using AI to shed light on cognition? What
are some disadvantages?
2. On pages 140-141, four key topics of AI research are identified (knowledge
representation, search, control, learning) and key aspects of each topic are listed in
terms of four questions (different for each topic). When reading about the three
examples of AI programs on the following pages (AM, MYCIN, HYPO), try to
identify which of the key questions apply to each program, and how they were
“answered” in each program. [ALSO, ASK YOURSELF WHETHER AN
ARTIFICIAL OR NATURAL INTELLIGENCE COULD BE CAPABLE OF
UNDERSTANDING THIS QUESTION!]
3. Look at the transcript from AM on p. 145. How do you think the program will
continue (e.g., NUMBERS-WITH-4-DIVISORS, SQUARE-ROOTS-OFNUMBERS-WITH-3-DIVISORS)? How might the program get back to the
concept of prime number? Does its thought process seem human like?
4. Why is backward chaining preferable to forward chaining in driving MYCIN’s
inference engine? (What would forward chaining look like?) How do you think
MYCIN decides which hypotheses to check first?
5. What is the role of dimensions in HYPO? Who creates and updates them?
6. Which program seems most intelligent, AM, MYCIN, or HYPO? Why?
7. What are some of the advantages and disadvantages of the main knowledgerepresentation methods (semantic nets, frames, scripts, production rules, FOPC)?
Give examples of how each makes some knowledge explicit, but leaves others
implicit. Give examples of the credit-assignment, grain-size, and right-primitives
problem in the context of each method. How can learning take place within each
method? Which methods seem most “human” like? What are the main arguments
against FOPC being the way humans represent and process their knowledge?
8. Taking the semantic net on page 155 as a starting point, how could you represent
the proposition “Olivia gave Whitman a red rose” using each of the knowledge
representation methods? Do some methods seem more natural (easy) than others?
Will the different representations lead to exactly the same information being
explicit and implicit in each case? (Just think about these questions a bit. I don’t
expect actual solutions.)
Goldsmith & Nevo (Sections 13.5)
Please look at section 13.5.1, and Palmer’s (1978) discussion of representation (this is the
only part that is not covered in Stillings).