Teachers are often convinced that their lessons are activity-packed, discussion-filled exercises in experiential learning. Pupils, meanwhile, are convinced that their teachers spend lessons delivering lectures and setting tests.
Teachers and pupils will usually view lessons differently, argues Danny Dockterman, of the University of California, Los Angeles, whose research explores this disparity of perception.
But, he says, the greater the discrepancy between what teachers and pupils think is going on during lessons, the less that class will be learning. And he believes that finding out how differently pupils and teachers perceive the same lessons should be a key element of teachers' professional development.
Mr Dockterman issued a survey to 659 eighth-grade (Year 9) pupils, as well as their teachers. He asked them questions about what went on during their lessons: how long the teacher spent addressing the class; how often the class spent completing worksheets; and how regularly homework was set.
It was not unusual, Mr Dockterman found, for individual pupils to give very different responses from their teachers. For example, a teacher might say that the class was given worksheets to complete two or three times a week, while one pupil might insist that there were worksheets every day.
In such cases, the discrepancy was a reflection on the pupil, rather than the teacher. "Those tend to be the lowest-achieving students," Mr Dockterman told TES.
But he also found that sometimes the whole class gave a different response from the teacher. "We're not talking about one student," he said. "We're talking about 20 students."
These lessons - where pupil and teacher perceptions were hugely misaligned - tended to be the ones that pupils enjoyed the least. In such cases, Mr Dockterman noted, it was the teacher's perceptions that should be questioned. "If you're asking how much homework you assign, and the teacher says 30 minutes a night and the student average is one-and-a-half hours - well, that's an issue," he said.
"By definition, that teacher is out of touch with how their students feel and how much homework is going on. That needs to be brought to the teacher's attention. Something isn't quite right in that classroom."
Russell Hobby, general secretary of the NAHT headteachers' union, agrees that surveys could be a helpful classroom tool.
"What we think we're doing and what people perceive us as doing can be very different," he said. "It's not that one version is right or wrong, but you need to know how you're coming across to others. Then you can reflect on what you're doing and make sure you're getting across what you want to get across."
The UCLA research found that when teachers were asked about elements of teaching they knew to be good practice - small-group discussion, for example, or hands-on investigation - they always insisted that these occurred regularly in their classes.
By contrast, pupils were more likely to say that they were being set multiple-choice tests and asked to listen to the teacher speak on a regular basis.
"It's completely normal that you should see test-taking rated as much more common by students than by teachers," Mr Dockterman said. "Students just don't like to take tests."
However, he believes that teachers could learn valuable lessons by examining where these discrepancies arise. "We talk about all these measurable outcomes, but just being in tune with your students is also really important," he said.
"Perhaps just sitting down with a teacher and saying, `Just so you know, your students are saying you talk to them for 30 minutes a day, and you're saying only 10 minutes a day.' That really needs to be brought to that teacher's attention. And there's no way to do that without looking at student responses."
Some schools are already starting to use technology to monitor teaching. In April this year, TES reported that a survey of 1,476 teachers by the NASUWT teaching union found that 8 per cent had CCTV in their classroom; 7 per cent of those said it was intended for monitoring teacher performance.
But Mr Dockterman believes that pupil surveys could be used as a less-intrusive way of measuring what goes on in the classroom. "Student surveys are very inexpensive and they're much easier - and less stressful for the teacher - than classroom observation," he said.
"I'm not saying it should be used for high-stakes purposes. But the more you can keep students and teachers on the same page, the better a classroom learning environment you will have, and the more students will enjoy what's going on there."
`Learning is a shared journey'
Tim Plumb, pictured, head of Woolwich Polytechnic School in South-East London, believes that simultaneous pupil and teacher surveys could be a valuable professional-development tool.
"Learning is a shared experience, a shared journey. If teachers and students think they're on different journeys, they're not going to end up in the same location," he says.
Mr Plumb believes that even superficially bland questions - such as how much time is spent on homework, worksheets or group discussion - can result in revealing responses. "Most students tend to be very honest when they're giving their views on what's happening in lessons," he says. "There's a high chance you're going to get valuable feedback."
He insists, however, that teachers need not fear pupils' judgements. "If this is a process you repeated a number of times, you'd be looking for improvement," he says. "Wherever the various starting points were, you'd expect student and teacher responses to get closer over time."