Pupils should be given the chance to rate their teachers on the quality of their lessons, according to a leading private school head.
Richard Cairns, Head Master of Brighton College is calling on the Government to make it compulsory for students to play a part in assessing the performance of teachers.
The move would help school leaders deal with under-performance in the classroom, he suggested.
In a speech to the Headmasters and Headmistresses' Conference (HMC) annual meeting today, Mr Cairns will say that he has introduced such a system at his own school.
Pupils at Brighton College are asked to fill in an online questionnaire about each of their teachers.
The form includes 22 statements or questions such as "my teacher sets clear expectations for my studies and the quality of my work", "my teacher caters for my learning style and my ability level" and "my teacher is passionate about his subject".
Students are asked to give a grade for each statement or question ranging from one, which is positive, to five, which is negative. They can also add their own comments.
It is thought to be the first time that students have been asked to help appraise their teachers in this systematic way.
The findings are collected and used as part of a teacher's appraisal, Mr Cairns says.
He will tell the conference: "It is used as the basis for discussions in appraisal meetings - either to praise good practice, or inform the setting of targets."
Ahead of today's meeting, Mr Cairns said: "All good heads know what the 'word on the street' is regarding good or bad teachers but we have no objective evidence except those that arise from lesson observations and exam results."
Lesson observation is a "seriously flawed approach", Mr Cairns argued, while exams results can say more about the culture of a school than how effective an individual teacher is.
Pupil appraisals are the only objective way of both praising good teachers and being able to have serious conversations with those that are not doing well, he suggested.
Mr Cairns said he is calling on the Government to make such a system compulsory in all schools "in order to help Heads deal quickly with underperforming teachers and also to provide positive, objective feedback for the best teachers which will aid retention and maintain enthusiasm".
He added: "We have put a lot of money into school inspection and we are very concerned about standards in schools but the key consumers - the pupils - are not consulted. That strikes me as crazy.
"We've got to get over this issue that young people might abuse such a system.
"Every good teacher I know trusts the pupils that they teach to act responsibly."
Mr Cairns said a similar system has been introduced at the London Academy of Excellence - a new state- funded sixth form in east London - which is co-sponsored by Brighton College.
Brighton College is a fee-paying boarding and day school for boys and girls aged three to 18.