Reading some isolated negative class evaluations from my least contented students can make me depressed. After all I have devoted my life to doing all I can to help my students realize their goals and dreams. I do suffer from a firm belief that this occurs not when they receive phony grades, but when they actually learn to use powerful ideas that will be valuable to them.
But when I think back on my own career, I realize the complaints may reflect a gap between what was expected by the teacher and what was assumed by the student. I went to Harvard college after 12 years in a mediocre southern school where I could almost literally copy my class reports out of the World Book the night before they were due, or answer questions on Ivanhoe after reading the Classic Comics version, and I always got A's. Needless to say, I did poorly in college. My first college composition, written in the habitual fashion, came back annotated: "Unoriginal and dull". All the professor had said was for us to summarize the plot of Plato's Republic and I did so, but the grader said we still should have known that at Harvard, an original critical essay was expected.
They let me in because I was smart and had potential. But lack of sophistication in writing, thinking, studying, and faithful class attendance, doomed me. After I got my first few poor grades, and found myself failing out and criticized for it, threatened with losing my scholarship, I began to blame my teachers as well, and I wrote some very scathing evaluations. But no one read them, because at that time at Harvard they were not part of the process. Evaluations were compiled independently and sold by the student newspaper, partly as amusement, but the university did not care what disgruntled students said. (This has subsequently changed, I think for the worse.)
It took me years to appreciate the high level of preparation and expectations my professors had brought to my classrooms. In the same way, when I teach a Fall classroom of "advanced placement" 1st semester Georgia Freshmen an off sequence 2nd semester calculus course, for which they have prepared in a Georgia high school AP class, they have no idea of the level of expectations I hold for them, even though I say so right off the bat, and in writing. It just takes longer than that for them to absorb what real study means and demands, when they have never been exposed to it.
I want them, as Andy said, to understand the ideas behind the subject and obtain a good mastery of technique, as well as a sound grasp of when to use what technique in practice. I want them to master theory, computation, and application. For many of them, all they expect is to be told to memorize some easy computations and see the same ones on a test, and then have me guarantee a certain percentage of A's regardless of performance.
When I give 4 tests and only score the best three, and then give graded homework and a final, spend dozens of hours grading them in detail, and prepare three grades, an overall average, an average omitting the homework, and a final exam grade, and assign them the highest of those three grades, many do not think I have "curved" the scores. To some of them, a curve means a predictable number of grades of a certain level regardless of performance, i.e. a grade relative to other students rather than relative to the material taught. I am even criticized when I will not give a C to a student who displays no discernible grasp of the most basic fundamentals of the subject.
These students are not evil, stupid, or lazy. But they have no idea at all what is expected from university students. Successful teaching is a happy marriage between the two parties, teacher and student, and it requires good communication. If only we could provide a better introduction to university academic life for our students, really convey to them what will be expected of them, how much harder the work will be, and exactly how to satisfy those demands, it might help.
Complicating this further is the inevitable tendency of professors willing and even forced to water down these expectations, in order to receive favorable evaluations. It is hard to answer the question, why is your class so hard when professor so and so (often a graduate student) gives all A's? (and does not ask any theory or hard computations.)
Maybe a summer preparatory program before the semester starts, or even a high school class or seminar taught by a professor in the senior and junior years, to hint at the different level of expectations. I have taught honors courses in high school for the best students and was initially asked to present it as a college level class. It was not long however until I was told I simply could not expect as much work as I was assigning from high schoolers. I.e. even the high school teachers who had asked for college level work from me backed off when they saw what it entailed. But my best students went on to successful careers at Harvard, Yale, Duke, and Chicago.
Here in Atlanta, we are still in the throes of a cheating scandal that revealed, in spite of the determined resistance of the public school system itself to the truth, that demands for steadily rising standardized test scores in elementary and middle schools had resulted in organized and wide spread cheating. Administrators returned tests with poor scores to teachers and teachers actually met after school at "test changing" parties, creating statistically implausible numbers of erasures from wrong to right. This scandal implicated literally hundreds of public school personnel.
The local paper then analyzed scores and wrong to right changes in school systems across America, releasing the data last Sunday. Some school systems had results that could have occurred naturally only with probability 1 out of a billion or more. Still, with a few exceptions, most of these school systems refuse to acknowledge any problems.
Teaching and testing present hard challenges. But in learning it helps if one actually wants to learn and is willing to try hard to do so, and in testing it helps if one actually wants to know the true results.