So you think teachers are unhappy, underpaid workers who, nevertheless, are opposed to merit pay.

Or maybe you think they are uptight spinsters dedicated to cramming their pupils' heads with useless information; or laissez faire liberals who have abandoned the traditional values.

Or perhaps you believe. . . .

No matter. To judge from a survey report I've just seen, whatever you think you know about teachers is probably wrong. Even Emily Feistritzer, the former teacher who directed the survey for the National Center for Education Information, admits being surprised by some of her findings.

To begin with, she reports, teachers are more satisfied both with their work and with their personal lives than most American workers, including most college graduates. They are not underpaid -- though many of them think they are -- since their earnings (about $136 a day for a 180-day contract) compare favorably with those of other college graduates (about $129 a day for a 250-day year). In any case, they are less likely than other workers to be in the profession for the money, and wouldn't give up their short work year for the extra income.

Most teachers are union members, but, contrary to union policy, they would prefer overwhelmingly that their pay be based on job performance in addition to seniority and educational credentials.

Three-fourths of all public-school teachers (and 60 percent of private school teachers) are married. Politically, teachers see themselves as more moderate than most Americans, even liberal on such social issues as abortion, the death penalty and prayer in schools, though two-thirds of them voted for President Reagan in the last election. More than 90 percent of the 1,592 teachers surveyed were white.

Satisfied that what you thought you knew about teachers is mostly wrong?

Well, I'm not. Not quite, anyway. Feistritzer said her survey's "overwhelming conclusion was that, whereas American workers in general gave top priority to money and job security in their work, teachers were a breed apart, marching to a different drummer. When asked what was most important to them on the job, the teachers responded that it was the opportunity to use their minds and abilities, to work with young people and see them develop, and to win recognition for a job well done."

But job security may be a low priority for teachers for the simple reason that teachers rarely lose their jobs, except in general staff reductions. And if money is not a major reason for going into teaching, it is the No. 1 reason for dissatisfaction with the profession. That isn't surprising.

Nor is the No. 2. complaint: the low status accorded teachers.

"What teaching may lack, far more than adequate pay," Feistritzer said, "is the dignity it once had and deserves to have again. Teaching is a noble occupation, and the people drawn to it are attracted for noble reasons that have little or nothing to do with monetary gain.

"In a materialistic society, this may strike some as heresy or, at best, naivet,e. But it is society's loss if over-emphasis on a status measured by personal income causes too many bright, enthusiastic young people to turn away from teaching because it is so widely and so persistently denigrated."

But that is simply a back-door admission that low pay is a major reason that teaching is a relatively unattractive field for college- trained young people. In practical terms, the dignity that Feistritzer says is lacking in the teaching profession may be just another way of spelling m-o-n-e-y.