Reply to thread

Message: [QUOTE="Florian G. Pflug, post: 4451092"] I believe that you oversimplified the problem, and therefore your math is wrong (or, rather, a too coarse approximation, as your results prove). From your paper: N... Number of Words. n... Number of banned words. r:=P[word w is banned]=n/N p:=P[slice of size x passes] = (1-r)^x. Your formula for p ((1-r)^x) assumes that the probability r is constant, while in reality it changes with every word you put into your slice. The probability of a slice of size x passing is the same as the probability that none of 100 words you randomly pick is banned. Now, while you pick (you pick only non-banned words, because you immediatly stop if you get a banned one), the ration banned/total for the _remaining_ set constantly changes. You can instantly see that your formula cannot be exact if you try to calculate the probability of a slice of size N passing. Your formulat gives (1-n/N)^N, which is probably quite small, but still greater than zero. The exact probability is obviosly zero (assuming n > 0) Additionally, the probability r changes everytime you find a non-banned slice. If, for example, you test 500 out of 100 words, and the slice passes, the being-banned probability of the rest of the words doubles. greetings, Florian Pflug [/QUOTE]