Chef

1
Chef

• Notes from Kris Hammonds chapter in ICBR

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Planning as Remembering

• What did you do the last time you wrote a
  program?
• What does an architect do?

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What to remember

• Successes
• Failures
• Goals
• The plan

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New theory of planning

• Search memory for plans that satisfy many goals
• Learn when recovering from errors
• Keep old plans around for reuse

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Plan indexes

• Successes and Failures
• The case based approach to finding an initial
  plan is to anticipate problems so the planner can
  find plans that avoid them
• Anticipate and avoid vs. create and debug

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Debugging still required

• Mistakes as expectation failures rather than
  planning failures.
• Debugging as explanation
• Repair as plan repair and knowledge repair.

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Learning/Adaptation

• Learn new plans that avoid problems
• New Features that predict problems
• Learn the repairs

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Plan retriever

• Best match
• Plan memory
• Goal similarity metric
• Goal value hierarchy

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Plan modification

• Modification rules
• Knowledge critics
• General plan knowledge

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Plan Storer

• Index under same goals as retriever will find
  them (natch)

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Plan Repair

• Knowledge of planfault to new plan
• Knowledge of planning language
• Side-effects, benefits, etc.
• Causal knowledge
• Explanation used to learn from failure (blame
  assignment)

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Example Recipe

• Goals Beef, broccoli stir-fry
• Retrieve beefgreen-beans
• Alter
• replace green-beans with broccoli
• Chop broccoli first
• Predicted goals tender beef, savory dish, crisp
  broccoli, salty dish, sweet dish, garlicky dish
• Cook
• Failure! Broccoli is soggy

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Failure explanation

• Whats wrong?
• Broccoli soggy, not crisp
• What led to this?
• Liquid in pan from beef
• Why did you do this?
• To cook beef

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Plan repair strategies

• Concurrent plans sometimes disable one anothers
  preconditions
• Possible plans
• Split-and-reform (multiple steps)
• Alter-planside-effect (replace step with new
  plan)
• Adjunct-plan (add new step)

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New plan!

• From stir fry broccoli beef, broccoli, garlic,
  soysauce, sugarto
• Stir fry broccoli
• Stir fry rest
• Add ingredients together

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Anticipating failure

• Broccoli-like veggies will cause this failure in
  the future
• Eg. Looking for a recipe for stir-fried chicken
  and snow-peas.