Representation has two things
- The Knowledge
- vocabulary
- The Content that goes into the presentation
AI Has many representations and each has its own affordance and constraint.
Introduction to Semantic Networks
- A: label objects in A as nodes x, y and z and describe the relationship between these objects with links.
- B: Do the same to B, label objects and the relationship
- between A and B: actions taken were described with the dash line.
- Key: use only the existing vocabulary
- the relationship of objects between C and 5 is not the same
Characteristics of Good Representations
Guards and Prisoners problem
- need to find out the legal and productive way of moving prisoners and guards from the left to the right side.
- the above moves were all legal, but two of them were not productive because they appeared in the previous steps.
- the power of semantic network representation is that it makes all the constraints of the states explicit and allows the problem be solved in a systematical way
- Please note that the state of the boat is also part of the system so that step 2 and 5 are not the same.
Represent & Reason for Analogy Problems
Back to the original question,
we know that 5 is not the correct answer because the semantic representation of A->B does not match C->5.
Now let's try C -> 2.
- we choose 5 as the best answer because the semantic network representation of C -> 5 matches the exactly that of A -> B. What if we don't find a 100% match?
Exercise: How do we choose a match?
- 5 is the answer: inner object disappear
- 3 can also be an answer: outer object disappear and inner object expand.
- Why most of the people will choose 5 instead of 3?
Choosing Matches by Weights
- 2 and 4 can both be an answer. However, C -> 2 is reflection which weights 4 points and C -> 4 is rotations which worth 3 points. In this case, 2 is the best answer because it has better weight
Connection
- To solve the problem, we need to save the representation of A -> B into the memory, also calculate the representation of C to all the options.
- The correspondent problem: one object in A corresponds to which object in B?
- In KBAI, the emphasis is on the relationships between object, not the features of an object (another weighting problem.
Assignment 1
The Cognitive Connection
How semantic networks connected to human cognition?
- Semantic networks are kind of knowledge representation which can be used to represent knowledge and problems, thus can be used to solve the problem. The human mind can also represent knowledge and problem, and solve problems.
- Semantic networks can expand, like human memory. initial input could activate certain nodes, expand to related nodes on the semantic networks, and form a pathway. [John wants to become rich. He got a gun]
20170121 first draft
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