Max_Powers 0 Posted August 23, 2008 Share Posted August 23, 2008 I've heard that on these types of exams you should not guess unless you can eliminate some choices. But it seems to me that even a guess among four choices is +ev..1/4 of the time you get it right and earn one point: 0.25 X 1 = +0.253/4 of the time you get it wrong and lose 1/4 point: 0.75 X -0.25 = -0.1875add ev = 0.25 + -0.1875 = +0.0625Compare this to your EV from leaving the question blank which is zero, and it looks to be like guessing is OK - of course the EV only increases if you CAN eliminate choices. The other option is that I'm a dumbass and doing this all wrong. Which is it? Link to post Share on other sites
jeff_536 3 Posted August 23, 2008 Share Posted August 23, 2008 One guess in four you'll be right for 1 pointthree guesses in four you'll be wrong for -.75.+.25 points for every four guesses = .0625/guess.looks right to me. Link to post Share on other sites
speedz99 145 Posted August 23, 2008 Share Posted August 23, 2008 Doctor! Link to post Share on other sites
Actuary 3 Posted August 23, 2008 Share Posted August 23, 2008 perhaps there are 5 answer choices on this exam? Link to post Share on other sites
SuitedAces21 2,722 Posted August 23, 2008 Share Posted August 23, 2008 perhaps there are 5 answer choices on this exam?mind = blown. Link to post Share on other sites
chrozzo 19 Posted August 23, 2008 Share Posted August 23, 2008 pagin LLY! Link to post Share on other sites
Max_Powers 0 Posted August 23, 2008 Author Share Posted August 23, 2008 perhaps there are 5 answer choices on this exam?Perhaps you can eliminate one choice?But even with 5 choices its a break-even bet.To look at it another way, if you randomly fill in 100 5 choice questions, are expected to get 20 correct for 20 points. The other 80 you lose 1/4 point each for -20. Overall, zero - the same as not answering any. It seems to me you should always guess, because at worst its break even with five choices if you are making a totally random choice. However, usually you can eliminate one or more choices, or at least get a "feeling" about one choice that is better than the others, pushing the odds into your favor. BTW the test I am speaking of is the high school AP exam (I'm a teacher) and several guides to the exam I've come across advise against guessing, or say only to guess if you can reduce the choices to 50/50. So I wonder if I'm missing something, but it doesn't look like it to me. Link to post Share on other sites
Balloon guy 158 Posted August 23, 2008 Share Posted August 23, 2008 Why are they making a wrong answer of less value than a right one?Shouldn't a wrong one be -1 and a right one +1?Stoopid schools Link to post Share on other sites
Yoda 1 Posted August 23, 2008 Share Posted August 23, 2008 The answer is obvious; you answer 0 questions and hand in a blank exam. This eliminates variance. Link to post Share on other sites
Dawson Leery 12 Posted August 23, 2008 Share Posted August 23, 2008 lol at people who get answers wrong Link to post Share on other sites
LongLiveYorke 38 Posted August 23, 2008 Share Posted August 23, 2008 david's new tv is enormous. Link to post Share on other sites
Actuary 3 Posted August 24, 2008 Share Posted August 24, 2008 Perhaps you can eliminate one choice?But even with 5 choices its a break-even bet.ok, I was making a guess as to why they used a 1/4 penalty.The rationale for not guessing then, would be that you could spend more time on ones you know.Obviously f you can reduce your choices, guessing is +EValso, perhaps ansers are written by experts who know what to put that leads people to guess incorrectly.Id have a pre planned guessing algorithm. Something that utilizes the fibonocci series works well. Link to post Share on other sites
phlegm 6 Posted August 24, 2008 Share Posted August 24, 2008 Any question u dont get right is wrong.or am i missing something? Link to post Share on other sites
Actuary 3 Posted August 24, 2008 Share Posted August 24, 2008 Any question u dont get right is wrong.or am i missing something?you seem to grasp it Link to post Share on other sites
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