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Yes, guessing based on partial knowledge might make you worse off. But as Yvain's footnote 1 says, replacing 30 "I don't know" answers with 30 purely random coi
by cousin_it 17y ago
Yes, guessing based on partial knowledge might make you worse off. But as Yvain's footnote 1 says, replacing 30 "I don't know" answers with 30 purely random coin-flip guesses has a 98% chance of improving your score. (I'd like to go on record saying emphatically that this statement doesn't need to be "tested". Recalculated, at most.) So if you have a coin in your pocket, it's pretty hard to rationalize answering "I don't know" to many questions instead of flipping the coin.
- deleted 17y ago[deleted]
- eru 17y agoOn some tests you get a zero score for not answering and a negative score for answering wrong. Balanced in such a way that uniform randomness gives you the same expected score as not answering.
- nkurz 17y agoI appreciate your response and voted it up. But I disagree that there is no benefit to actually testing his hypothesis. The mathematics don't need to be 'tested', but perhaps the priors do? For example, how certain are you of the assumption that the questions that we need to flip the coin for are evenly distributed between true and false? It seems plausible that a test might have a bias whereby the harder questions are predominately one answer or the other. How large would this effect have to be to overwhelm the 2% probability? Would you trust your grade on the presumption that this effect can be ignored? What about your life? For the record, I agree with Yvain's advice. I did just fine on the SAT's, partly because I followed the mathematically correct advice that one should guess if one can eliminate at least one of the 4 choices. But I wouldn't proclaim that this strategy needs no testing just because the mathematics are correct.