> This has nothing to do with whether the students can understand it easily or not. He could be communicating effectively (e.g as Knuth does in his Art of Compu

> This has nothing to do with whether the students can understand it easily or not. He could be communicating effectively (e.g as Knuth does in his Art of Computer Programming books) with the students still not getting it. If the audience doesn't get it, then the communication is ineffective, period. You can't just send corrupt data to a server that doesn't understand it and say that the communication was successful -- same deal with humans. [1] Maybe there are some topics that the students will need to 'sleep on' in order for it to really sink in, but that's not the same as them 'not getting it'. Being someone who's taught myself, I guarantee you that not only is there a difference between those two states, but that you can actually see them in action - as a teacher. If you get to know your students, you can tell when they successfully process enough of the information to be able to figure it out themselves later, from when they just don't get anything you're saying. If you leave things off thinking they could figure it out themselves when they actually got no meaningful data to work with off you, then it doesn't matter how long you give them, they still aren't gonna get it. That is faulty communication. Good teachers can sense this happening and correct for it. Unfortunately, a lot of teachers seem to rely on this idea as a crutch to prevent them from the work of trying to dig into their students' psyche, when the reality is that you really need to be able to do that to become a good effective communicator/teacher. [1] There is also the fact that the audience may not be fully prepared to understand what you're telling them, but hey, prerequisite knowledge is part of communication too (like a server protocol would be). Fact is, if you're failing to communicate effectively as a result of some unmet prerequisite knowledge, that means some other teacher down the line in the student's life must've dropped the ball on communication too. As you might expect, this can easily snowball quite quickly and lead to a total communication breakdown by the time a student enters the higher levels of education. Thus, effective communication should be a hugely important part of a teacher's skill set, cause even the slightest communication screw-up can trigger a whole chain of breakdown events for a large number of students in the future, which only serves to bite all of society in the ass.