1 / 8

CPSC 327

CPSC 327. Week 2 AI as Representation and Search. Knowledge Representation. Most important part of AI How do we get objects and relationships from the world into the computer. Suppose we have a stack of blocks: A B C And this goal C B A And these rules:

tyrell
Download Presentation

CPSC 327

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript

  1. CPSC 327 Week 2 AI as Representation and Search

  2. Knowledge Representation • Most important part of AI • How do we get objects and relationships from the world into the computer

  3. Suppose we have a stack of blocks: A B C And this goal C B A And these rules: • If x is clear, put x on the table • If x is clear and y is clear, put x on y

  4. Notice that we say nothing about color, texture, weight. A KR is an abstraction of the essence necessary for solution from objects that exist in the world So, we have only • Name of the block • Position of the block relative to other blocks

  5. Given the initial state and repeated application of rules, we can generate this graph: A B C R2 R1 B C A R2 R1 R2 C B A A B C B A C R2 R1 A B C

  6. Called a State Space Could • Assign a metric to the goodness of each state, depending on how close it is to the goal • Representing each state with a 3X3 array • Notice • Representation is a surrogate for the real world • Representation is an approximation. The only representation that’s error-free is the thing itself • Representation selects important properties • Representation sanctions two inferences • Blocks are/are not in goal state • Some states are closer to goal than others

  7. Many Representation Schemes in AI • First order predicate logic • Semantic nets (structured inheritance networks) • Frames and Scripts (Stereotypes) We’ll look at each.

  8. Important Point AI is concerned with: • Qualitative rather than quantitative problem-solving • Reasoning rather than calculation • Organizing large amounts of varied knowledge rather than implementing a single well-defined algorithm • Good-enough rather than optimal solutions • Means that representation must have structures that are more complex than traditional representational formalisms like arrays.

More Related