Menu
I have the book Artificial Intelligence: A Modern Approach (by Stuart Rusell). I am reading chapter 16, "Making simple decisions", but I do not get the main idea of the utility theory, can you provide a detailed example?
417
Utility theory explains individuals' choices and measures their level of satisfaction from consuming a good or service. The level of satisfaction is measured in units called 'utils. ' Marginal utility is the satisfaction that a person receives from consuming an additional unit of the same good or service.
Example of Expected Utility An individual calculates the probability of expected outcomes in such events and weighs them against the expected utility before making a decision. For example, purchasing a lottery ticket represents two possible outcomes for the buyer.
Utility functions are a product of Utility Theory which is one of the disciplines that helps to address the challenges of building knowledge under uncertainty. Utility theory is often combined with probabilistic theory to create what we know as decision-theoretic agents.
Expected utility theory is a theory about how to make optimal decisions under a given probability of risk. It has a normative interpretation which economists used to think applies in all situations to rational agents but now tend to regard as a useful and insightful first order approximation.
The main idea of utility theory is really simple: an agent's preferences over possible outcomes can be captured by a function that maps these outcomes to a real number; the higher the number the more that agent likes that outcome. The function is called a utility function.
For example, we could say that my utility for owning various items is:
u(apple) = 10
u(orange) = 12
u(basketball) = 4
u(macbookpro) = 45
Economists (usually) consider humans as utility-maximizing agents. That is, we are always trying to maximize our internal utility function.
Once you have these numbers, then you can mix them in with probabilities and talk about expected utilities, optimal strategies, discounted future rewards, and many other fun things.
If you want to learn more, pick up a textbook on game theory, or read the first chapter of this agents book.
115
Dave Mark has written a whole book on utility theory for game ai: http://www.amazon.com/Behavioral-Mathematics-Game-Dave-Mark/dp/1584506849/ref=sr_1_1?ie=UTF8&qid=1415095272&sr=8-1&keywords=dave+mark
He also has some public lectures up, along with Kevin Dill: http://intrinsicalgorithm.com/IAonAI/2013/02/both-my-gdc-lectures-on-utility-theory-free-on-gdc-vault/
42
If you love us? You can donate to us via Paypal or buy me a coffee so we can maintain and grow! Thank you!
Donate Us With
