Talk:Error detection and correction

The following paragraph is slightly misleading:

"Information theory tells us that whatever be the probability of error in transmission or storage, it is possible to construct error correction codes in which the likelihood of failure is arbitrarily low. It gives a bound on the efficiency that such schemes can achieve."

The problem with this is that in case the error is "perfectly random", e.g. for a bit channel, if the error probability per bit is >exactly< 1/2 and bit errors are independant of each other, then there is no code that can preserve >any< information in the channel, e.g. whatever the sender put into the channel, the receiver would only get perfectly random "noise".

Higher bit error probabilities are ok again, because inverting the arriving signal can then be used to invert (1-p) the error probability p to less than 1/2.