This column emphasizes—as does virtually every other forum for discussion of teaching—what works in the classroom. We invent a great new wheel that takes our students just where we want them to go. So, we want to roll it out for public display. Some days I can hardly wait to school a colleague in my successful strategy. And I've been grateful to be schooled myself by other people's ideas. I remember one Perspectives column about 10 years ago that outlined a first-day exercise in which the students were asked to "draw history." I took it up on the spot and used it to great success for several years. It's fun and it's easy to talk about our successes.

I know that I'm a good teacher. If I'm truthful, though, I have to admit that the proportion of my teaching life that I spend feeling brilliant is exceeded by the proportion when I feel troubled or worried or even insecure. At one time I hoped that I would get beyond these feelings. I think I hoped that as I grew more confident, my anxieties would disappear.

I am much more confident now than when I started. On the very first day that I taught the history survey, I walked into class with every word planned out. "Good morning," I wrote in my notes, "my name is Annette Atkins." Was I afraid I'd fail to greet the students or forget what I'm called? I don't write it down anymore because I know that I'll remember. I also know that if I don't remember it won't matter too much. I had a neighbor boy a few years ago who stood on the edge of the diving board for 10 minutes before getting up the courage to take his first jump. On his second attempt he marched himself right up there and jumped without a pause. "I'm always brave the second time," he explained.

When we teach we're always walking out to the edge of the diving board. Practice and repetition are the obvious ways to make ourselves feel more secure. But repetition can also be the antithesis of good teaching. Nothing sounds the death knell on teaching more dolefully than always doing the same things the same way.

Good teachers leave behind the safety of the known and try something new. We teach from the same textbook for a while and then try another or we abandon a reader and use primary documents or try one novel and then try another. We try lecturing and small-group discussions or free writing or role playing. We take up new topics, ask new questions, rearrange the structure/outline/syllabus. We ask different exam questions—in-class this year, take-home next time, no exams and all papers another time. Then maybe we even decide to teach a completely new course. I thus get to reinvent many new wheels even if they don't always roll in the direction that I want, or as they sometimes do, actually roll me right into disaster.

Teaching fosters insecurity in other ways, too. It's a job where we can't know for certain how well we're doing (or actually what "doing well" means). We can know if students pass or fail, but we can't know if they're really learning or what they're learning or if what they're learning has anything to do with what we are teaching. From time to time, I have had students hand in their class notes just to see what they're hearing/thinking/understanding in my class. I don't recommend it!

It's easier to know if we're succeeding if we're aiming especially at the mastery of content (whether or not the students can list the generals in the Civil War can be tested and measured) than if we're trying to measure skills not so easily quantified; if, for example, we are trying to get the students to think historically, to develop their capacity for understanding complexity, to understand the extent to which people's opportunities and choices are shaped by their historical contexts, etc. These are so much harder to measure or even to know. We can test our students on these things, but some of what they'll learn they may not know that they've learned for a long time after they've left us. We hope that we plant seeds that grow, but we don't often see whether they actually do. Besides, sometimes we plant corn and it turns into wheat.

Lecturing one day in 1974 in a constitutional law class at Indiana University, Maurice Baxter discussed a Supreme Court case that was ostensibly about the regulation of steamboats but was really an argument about whether the states or the federal government had the authority to regulate slavery. Slavery was simply too dangerous to talk about, so people were, in effect, talking in code. Well, I can't tell you how often that little lesson has helped me understand conversations in both my personal and my professional life. Did Professor Baxter ever know how valuable that lesson was to me? Probably not.

There are, at the same time, so many ways to know that we haven't succeeded: the sleeping student in the back row; the one who skips class unless we have a rigid attendance policy; the one who stops by to see if I'm going to do "anything important" on Friday when they need to leave early for their high school's big game. Then there are those dreaded student evaluations (I prefer to call them surveys, in part to defuse their power). I have long since forgotten most of the positive ones (though I admit to having tucked a couple into my "nice notes" folder), but I can recite from memory some of the others (suggestions for improving the class: "get a new teacher," one student scrawled). The most painful examples for me, though, are the students whom I just can't capture, who survive a whole semester without ever being engaged, who are relieved to have another required course "out of the way." OK, maybe these things shouldn't demoralize me, maybe they aren't signs that I've failed, but I can't just shrug them off either.

In teaching, there is also the peculiarity of the completely unpredictable relationship between planning and outcome. Some classes for which I've planned meticulously have gone really well; at other times my preparation seems to get in the way. Sometimes when I feel a little underprepared the class flounders—of course! On other occasions, though, it's a great success. Why this time and not that? I don't know. In other parts of my life—and in my research, too—there is a greater connection between my efforts and the results. In teaching, almost never.

Teaching is an occupation that puts a premium on knowledge, yet every day there is so much that I can't know and can't control. There is no predictable relationship between what I do and what they do; there is no sure way that I can effect what I intend.

So, I say that I have the best job in the world and most days I even mean it. But parts of it are really hard and I don't mean the papers, the preparation, the labor of it all. I mean emotionally. I feel my work and some days it doesn't feel very good. I finally understand, though, that it's part of the job. Maybe there's room to talk about this part as well as about our successes?