tag:blogger.com,1999:blog-1689592451067041352.post197353713336391459..comments2016-12-16T22:25:29.818-08:00Comments on DiEbLog: Five Years of "The Search for a Search"DiEbhttp://www.blogger.com/profile/02099109109735165335noreply@blogger.comBlogger6125tag:blogger.com,1999:blog-1689592451067041352.post-88145934963990219982015-05-15T08:55:20.812-07:002015-05-15T08:55:20.812-07:00Hi - I thought I made one short response that has ...Hi - I thought I made one short response that has not appeared but maybe it did not take. I think I have got it now. <br /><br />Strategy M1 is: try as hard as you can to track the pea and choose the shell you think it is under (which as it turns out with these probabilities will mean you almost always choose left or middle).<br /><br />Strategy M2: is pick a shell at random.<br /><br />M1 is better because two of the shells have a high correlation between appearing to have the pea and actually having the pea.Mark Frankhttp://www.blogger.com/profile/07117994136165938870noreply@blogger.comtag:blogger.com,1999:blog-1689592451067041352.post-43911977876739503892015-05-15T04:14:33.182-07:002015-05-15T04:14:33.182-07:00I'm afraid I cannot follow. I edited my post t...I'm afraid I cannot follow. I edited my post to clarify my position: it is just a traditional shell game ("Hütchenspiel"). If you correctly announce the shell under which there is the pea, you win - you have performed a successful search. DiEbhttp://www.blogger.com/profile/02099109109735165335noreply@blogger.comtag:blogger.com,1999:blog-1689592451067041352.post-11599636481805523792015-05-15T04:11:56.466-07:002015-05-15T04:11:56.466-07:00I hadn't thought about where Winston Ewert wou...I hadn't thought about where Winston Ewert would post his answers, but Uncommon Descent seems to be an obvious choice. Though it is not ideal, Winston is at least trying to talk to "the other side"!<br /><br />My banning was just coincidental (though perhaps convenient): I asked three times about the disappearing comments of Aurelio Smith, and only after I got banned I realized that it wasn't a technical problem that my questions vanished quickly!DiEbhttp://www.blogger.com/profile/02099109109735165335noreply@blogger.comtag:blogger.com,1999:blog-1689592451067041352.post-61415202202224169152015-05-15T02:30:14.665-07:002015-05-15T02:30:14.665-07:00I don’t think it is particularly relevant to your ...I don’t think it is particularly relevant to your general point but I think your sums could be wrong. The correct answer depends on several things which need to be defined more closely. What counts as a successful search? What do you mean when you say the probability of finding the pea is 1/1000? What do you know? What are the searches you are comparing? Here are some of the options as I see them. <br /><br />What counts as success?<br /><br />Is it choosing the shell which contains the pea<br /><br />OR<br /><br />Choosing the correct shell and finding the pea i.e. choosing correctly and knowing you have chosen correctly.<br /><br /><br /><br />Meaning of probability of finding the pea is 1/1000<br /><br />Do you mean the probability of finding the pea after you have chosen the shell and it is turned over (kind of weird but conceivable)? Or do you mean if the pea goes under that shell what is the probability of you seeing it happen?<br /><br /> <br /><br />What you know<br /><br />Suppose the shells are A, B and C.<br /><br />1) You know that if the pea is under A or B you will see it there. (In which case the logical strategy is if you see the pea under A or B then choose A or B otherwise choose C. Probability of success is 100%. I guess this is not what you meant.)<br /><br />OR<br /><br />2) You know that for two of the shells (but you don’t know which ones) if the pea is under them you will see it there. <br /><br />3) You know nothing in advance but learn something if the pea is under shells A or B.<br /><br />Practically speaking 2 and 3 come to the same thing. <br /><br /> <br /><br />Search strategies<br /><br />In the case of ( 2) and ( 3) I guess the two possible search strategies are:<br /><br />X) Choose a shell at random (even if you can see it is under another one!)<br /><br />Y) If you can see the pea under a shell choose that one, otherwise choose a shell at random<br /><br /><br /><br />Calculation of Probabilities<br /><br />If success is choosing the correct shell<br /><br />The P(success) for X is 1/3 and P(success) for Y is 7/9 (1/3*1 + 1/3*1 + 1/3*1/3)<br /><br />If success is finding the pea & p(1/1000) means probability of seeing the pea go under the shell then<br /><br /> P(success) for X is 1/3 and P(success) for Y is 7/9 – same argument as above<br /><br />If success is finding the pea & p(1/1000) means probability of finding the pea once it is turned over<br /><br /> P(success) for X 2/9 (1/3*1/3 + 1/3*1/3 + 1/3*1/3*1/1000) and P(success) for Y is 2/3<br />Mark Frankhttp://www.blogger.com/profile/07117994136165938870noreply@blogger.comtag:blogger.com,1999:blog-1689592451067041352.post-90722678973241092932015-05-14T15:26:55.437-07:002015-05-14T15:26:55.437-07:00Oops. I linked to Ewert's "Ask Dr Ewert&q...Oops. I linked to Ewert's "Ask Dr Ewert" post at Uncommon Descent, which links to <a href="https://www.google.com/moderator/#15/e=21afd2&t=21afd2.40" rel="nofollow">Ask Dr Ewert</a> at soon-to-be-decommissioned Google Moderator.Tom Englishhttp://www.blogger.com/profile/03887540845396409340noreply@blogger.comtag:blogger.com,1999:blog-1689592451067041352.post-46989956133444944202015-05-14T15:11:33.625-07:002015-05-14T15:11:33.625-07:00I hope you don't mind my observation that your...I hope you don't mind my observation that your post relates to one of three questions you posed at <a href="http://www.uncommondescent.com/intelligent-design/ask-dr-ewert/" rel="nofollow">Ask Dr Ewert</a> (link expires June 30, 2015). Ewert, who collaborates with Dembski and Marks, evidently intends to answer selected questions at Uncommon Descent. You've been banned there since raising the questions, have you not? Correlation does not imply causation. But if you cannot comment on his answers to your questions, then he will in fact have ensconced them in a sham forum.Tom Englishhttp://www.blogger.com/profile/03887540845396409340noreply@blogger.com