BN1 - Bayesian networks A simple graphical notation for...

This preview shows pages 1–5. Sign up to view the full content.

Bayesian networks A simple, graphical notation for conditional independence assertions and hence for compact specification of full joint distributions Syntax A set of nodes, one per variable A directed, acyclic graph (link implies direct influence) A conditional distribution for each node given its parents Conditional distributions For each X i , P(X i |Parents(X i )) In the form of a conditional probability table (CPT) Distribution of X i for each combination of parent values

This preview has intentionally blurred sections. Sign up to view the full version.

View Full Document
Example Topology of network encodes conditional independence assertions Weather Cavity Toothache Catch Weather is independent of the other variables Toothache,Catch are conditionally independent given Cavity
Example I’m at work, neighbor John calls to say my alarm is ringing, but neighbor Mary doesn’t call. Sometimes it’s set o by minor earthquakes. Is there a burglar? Variables: Burglar, Earthquake, Alarm, JohnCalls, MaryCalls Network topology reflects “causal” knowledge A burglar can set the alarm o An earthquake can set the alarm o The alarm can cause Mary to call The alarm can cause John to call

This preview has intentionally blurred sections. Sign up to view the full version.

View Full Document
Example (Contd.)
This is the end of the preview. Sign up to access the rest of the document.

{[ snackBarMessage ]}

What students are saying

• As a current student on this bumpy collegiate pathway, I stumbled upon Course Hero, where I can find study resources for nearly all my courses, get online help from tutors 24/7, and even share my old projects, papers, and lecture notes with other students.

Kiran Temple University Fox School of Business ‘17, Course Hero Intern

• I cannot even describe how much Course Hero helped me this summer. It’s truly become something I can always rely on and help me. In the end, I was not only able to survive summer classes, but I was able to thrive thanks to Course Hero.

Dana University of Pennsylvania ‘17, Course Hero Intern

• The ability to access any university’s resources through Course Hero proved invaluable in my case. I was behind on Tulane coursework and actually used UCLA’s materials to help me move forward and get everything together on time.

Jill Tulane University ‘16, Course Hero Intern