this was actually a a formulation introduced by Claude Shannon here at MIT during his master's thesis as well and this was about 50 years ago it's still being used very prevalently today and the idea is it just again compares how different these two distributions are so you have a distribution of how how likely you think the student is going to pass and you have the true distribution of if the student passed or not you can compare the difference between those two distributions and that tells you the loss that the network incurs on that