CS 6766: Reasoning About Uncertainty - Fall 2015

Instructor: Joe Halpern, 414 Gates, halpern@cs.cornell.edu, 5-9562
Admin: Randy Hess, 323 Gates, rbhess@cs.cornell.edu, 5-0985;
TA: Matvey Soloviev, msoloviev@cs.cornell.edu
Classes:Tuesday, Thursday 1:25 - 2:40, 362 Hollister
Office hours
Halpern: TBD
Soloviev: TBD
Text: Reasoning About Uncertainty (Halpern). (It should be available in the bookstore. The paperback version is marginally better (and should be cheaper), but the hardcover version is OK too. The paperback version corrects a number of typos and minor errors in the hardcover version.) Unfortunately, there are still typos in paperback version; a list of those that have been discovered so far can be found at http://mitpress2.mit.edu/catalog/item/default.asp?ttype=2&tid=10758&xid=13&xcid=8006. I'm sure there are even more lurking in the book; if you discover any, let me know!

Grading: There will be no tests or final examination. There will be problems handed out, typically 3 every Thursday, from the book. The grade will be based completely on your performance on the problems. Problems are always due two weeks after they're handed out. If you hand them in one week after they're handed out, I will grade them and return them the following week. You can then redo any problem that you seriously attempted and hand it in again, to improve your grade. On a redo, you can get a maximum of 1 point less than the original value of the problem. (That is, if the problem was originally out of 10, the most you can get is 9.) I will take the higher grade.

Academic Integrity: It's OK to discuss the problems with others, but you MUST write up solutions on your own, and understand what you are writing.

Course Outline: We will be following the text very closely. Very roughly, we will be covering one chapter per week. Topics include approaches to representing uncertainty, updating, representing uncertainty in multiagent systems, logics of reasoning about uncertainty, and default reasoning. The material should be relevant to philosophy and game theory as well as CS; I'll try to bring out the connections as we go along.

Webpage: The course URL is http://www.cs.cornell.edu/courses/cs6766/2013sp. Assignments will be posted there, as well as other class information.



Note: you can find your grades and solutions to the homework on CMS.

  • Week 1: handed out 8/27; due 9/10 (hand it in 9/3 for a second chance)
    • Read Chapters 1, 2.1-2.3
    • Do 2.5, 2.14, 2.16. In 2.5, change the second two occurrence of >= to >.
  • Week 2: handed out 9/3; due 9/17 (hand it in 9/10 for a second chance)
    • Read all of Chapter 2 (inclding the exercises and notes at the end).
    • Think about (but don't hand in) 2.25
    • Do 2.28, 2.36, 2.57(a),(c),(d).
  • Week 3: handed out 9/10; due 9/247 (hand it in 9/17 for a second chance)
    • Read all 3.1-3.4
    • Do 3.2, 3.7, 3.8
    • You can now post homework on CMS!
    Week 4: handed out 9/17; due 10/1 (hand it in 0/24 for a second chance)
    • Read Chapter 3
    • Do 3.16 (5 points), 3.23, 3.41 (5 points), 3.44
    • Don't forget that you an now hand in homework on CMS.
    • Steve asked if the only time that Bel|B = Bel||B iff Bel is a probability measure. That was an interesting question! It turns out that it's almost, but not quite true. The easiest way to think about this is to observe Plaus(A||B) = Plaus(A \inter B)/Plaus(B), while Plaus(A|B) = Plaus(A \inter B)/(Plaus(A \inter B) + Bel(A^c \inter B)). Thus, Plaus|B = Plaus||B iff, for all A, either Plaus(A \inter B) = 0 or Plaus(B) = Plaus(A \inter B) + Bel(A^c \inter B). It turns out that this latter ocndition holds iff, for the mass function m corresponding to Bel, either (a) the only sets that got positive mass are singletons (so Bel is a probability measure) or (b) the only sets that get positive mass are either singletons or the whole space S. It's not that hard to prove this; if you're interested, I can show you the details offline.
    Week 5: handed out 9/24; due 10/8 (hand it in 10/1 for a second chance)
    • Read Chapter 4
    • Do 3.47, 4.18, 4.24(a),(b),(c)
    Week 6: handed out 10/1; due 10/15 (hand it in 10/8 for a second chance)
    • Read Chapter 5
    • Do 5.5, 5.8, 5.10 (There's a typo in 5.8: the subscript on E should be calligraphic P, not \mu; there's also a typo in 5.5: there should be a twiddle over the 0 in (b').)
    Week 7: handed out 10/8; due 10/22 (hand it in 10/15 for a second chance)
    • Read Chapter 6.1-6.5
    • Do 5.15, 5.19, 6.4. Think about (but don't hand in) 5.38.
    Week 8: handed out 10/15; due 10/29 (hand it in 10/22 for a second chance)
    • Read Chapter 6
    • Do 6.6 6.7, 6.14.
    Week 9: handed out 10/22; due 11/4 (hand it in 10/29 for a second chance)
    • Read Chapter 7
    • Do 6.18, 7.11, 7.21
    • Note that class is canceled for next Thursday (10/29), but homework is still due. My office hours on 10/28 are also canceled (I'm going to Taiwan for a few days).
    Week 10: handed out 10/29; due 11/12 (hand it in 11/51 for a second chance)
    • Do 7.22, 7.26,
    Week 11: handed out 11/5 due 11/19 (hand it in 11/12 for a second chance)
    • Read Chapter 8.1-8.5
    • Do 8.5, 8.34 (do it only for \M^{ps}, \M^{poss}, \M^{tot}, and \M^{qual}), 8.48
    Week 12: (final homework!) handed out 10/12; due 12/1 (hand it in 10/19 for a second chance)
    • Read Chapter 10
    • 8.38, 10.18, 10.24