I like to cut the grass. It's a good thing, because ours has looked better after cutting for a month or so already this year.
Straight man (you youngsters probably need to look up that term): "Why do you like to cut the grass?"
Me: "Because when I finish it, I feel as if I have accomplished something."
I know when I have cut the grass, but I never know when I have taught. I haven't taught if no one has learned anything, and it's often hard to know if they have. No matter how good a job I may think I have done in teaching, I seldom know what the real results were. (I'm musing about teaching college undergraduates. I don't know much about teaching at "lower," or "higher," levels.)
Straight man: "But don't you know when you give a test?"
Me: "Not really. I may know how many points they got on a test, but I usually don't know how good a measure the test was. I also don't know how many points they might get on the same test in two weeks, or ten years. Lots of people cram stuff into their brains, take a test, and forget much of the material, seemingly before they get through the classroom door on the way out after taking the test. They didn't really learn it, so I didn't really teach it."
Sm: "Well, what about the course evaluations? Don't they tell you something?"
M: "Sure. But maybe what they tell me is how much I have pandered to undergraduate sensibilities, not how good a job I have done in teaching. Besides, how are students in, say, physics, supposed to know what a good (or bad) teaching job looks and feels like? I'm the only college physics teacher they have ever had."
My friend Fred, a retired pastor, says the same sort of thing about mowing the grass, in relation to pastoring.
Teaching should be measured by the impact the teacher, and the course experience, have on the future life of the student. In some cases, finding out how students did on qualifying exams would be a valid measurement of this. Did she get into medical school? Is he qualified to teach? The trouble with that is that some people would have probably qualified even without my course. And, I hope, many of them will have done some serious review on their own before taking the test, so that if they do well, it's because of their own work, not just the teacher's. There are other measures of impact. Do students come to class unsure of their vocation, and have a revelation, while in my class, that they want to enter some field related to the subject? That won't happen often, but, if it does, it often may be because of some good teaching.
Some students probably don't need good teachers. They are going to do well, almost no matter what. They are intelligent, hard working, organized, and know what they want to accomplish. They may succeed in spite of the teacher, not because of her. The real test is the have-nots, or, rather, the have-littles. Can a good teacher take someone who doesn't know how to study, who doesn't really want to be in college, and turn him into a student? Sometimes. Not often. And, if it doesn't happen, is it really the teacher's fault?
I could talk about other measurements. Did their lives change while in my classes? Did they start thinking, studying, and creating on their own, as a result of taking my class? Did they suddenly see possibilities they hadn't seen before? Perhaps such things happen, but, if they do, they are rare, even for the best of teachers, and the teacher would seldom or ever know if they had happened when evaluating her teaching at the end of the day, often not even at the end of the year. If I had been Jesus, I wouldn't have been very optimistic about the future of the church when I went to the cross. Had they learned anything?
Trying to teach is like throwing bread on the water. (Ecclesiastes 11:1) Sometimes you'll find it after many days. Sometimes, someone else will find it. Sometimes, the fish eat it, or it just gets soggy and sinks to the bottom, to decompose slowly.
Don't get me wrong. I have loved teaching. I have come to know a lot of people who are worth knowing, some for a short time, some for almost a lifetime. I have been praised and loved. I have been, in large part, my own boss. I have tried to teach material I really cared about. I have seen what I really believe were flashes of insight, changes of direction, realizations of potential, sudden desires to find out something not required. And, when I didn't see those things, they may have been there, but I just didn't notice, or they may have started there, but become noticeable years later, when she was in her own classroom, teaching 4th grade science. Yes, teaching has great rewards. The greatest reward, though, is that Someone, a great teacher, asked me to do it, and I tried to answer by doing.