Thank you for this X. During spring break if I get time, I will try and do an audio recording and load it to Sound cloud. Deal :)

No disagreement at all. I don't think a teacher should ever give up on a student. So if you are trying, and struggling, we should and most of us do extend as much support as we can. Every F has been a personal failure on my part.

But sometimes as part of our signaling as instructors, the only way to get through to a student to let him know that he didn't meet the bar. Not because of trying. Because of not trying, or not making the effort, or occasionally because they felt that they would get a pass one more time. In such cases the F often serves a wake up call. "You can fix this if you start now. Start now before its too late."

In skill based courses, the issue is not effort. The issue is the time commitment required to pick the skill. A swim coach or life guard should be able to swim and save a drowning child on the deep side of the pool. When we pass or certify a coach or a life guard who doesn't know how to swim, and society relies on that certification, we fail in our roles as instructors.

To the extent possible across 30 years I have gone out of my way to pass all my students. You really have to work at it to get an F from me in my courses.

Less than 20 across 4,000+ students all over the world. I wouldn't change those grades even today.