The quantitative measure of information is dependent on our notion of the word “information “. Eg. Consider a communication system transmitting msg m1,m2,m3 …….. Let the probability of occurrence of these msg be P1, P2 ….etc resp. Then the amount of “information” transmitted through the signal Mk is : -

$I_k=\log_2⁡ \big(\frac{1}{P_k }\big)$

$P_k$ = probability of occurrence of mk