Yes, let's say there exist 100 students. 50 work hard, and get a signal from a normal distribution N(h,2), h=(0,10). The other 50 shirk and get a signal from a normal distribution N(0,2). That is, if you work hard the signal is higher (for later use).
I am modifying the parameter h, to go from 0 to a very high number. When h is very high anyone who sees the signal can tell for sure the student work hard.
I could use as a measure of how easy is to tell that a student worked hard by using the difference in mean. But I would like something between 0 and 1.