Warm-Up 6, Due Thursday, April 19, before class.

Warm-up questions usually either address material we handled during last class, or material you were to read in preparation for class, or you are supposed to answer questions based on your common sense alone. Please answer each question in three or more sentences. It is OK to answer 'I don't know' - but try to tell me why you are confused! No late Warm Ups are accepted for any reason, and only those submitted electronically through this web page (or by email, if the web page has technical problems) are considered.

Your Name:

Question 1

What is a position in a game? What is an information set? Do you understand what the difference is?

The following three questions refer to the game given by the expensive form shown below:

Question 2

When Ann has to decide between her moves A3 and A4, either Ann played A1 before, followed by the random move R2, or Ann's move A1 was followed by the random move R1 and Beth's move B2. How much of this game history is known to Ann when she has to decide? Does she know that she played A1 before? Does she know whether R1 and R2 was played, and in case of R1, whether Beth played B1 or B2?

Question 3

How many information sets does Ann have in the game above? How many information sets does Beth have. Note that positions that have perfect infomation (that are not inside of these bubbles) are supposed to be their own information set.

Question 4

How many pure strategies does Ann have in the game above. Describe one. How many pure strategies does Ann have?