It's 11am on a wet Thursday and Dawn Perry is steaming through a lesson on the heart and circulation. Her class at Peacehaven Community School is watching intently. Five miles away in Brighton, so too are 42 trainee teachers and Mike Willson, their lecturer, who is explaining the finer points of her technique.
The pound;400,000 system could be the future of teacher training and continuing professional development, and teachers, lecturers and trainees are raving about it.
"You get these teaching DVDs with Stepford students who are perfectly well-behaved. It does not give you a real-life situation," says Paul Meredith, a 33-year-old trainee.
The idea grew from necessity, when asbestos removal evicted the Sussex University science PGCE department. Temporarily based in the new and then largely empty Peacehaven school, lecturers discovered the benefits of trainees seeing more lessons and discussing problems with real teachers.
Back on campus, the department was desperate to carry on the new way. The theory is simple but the technology is not. It has taken several years and a large charitable grant to create the system. Lessons from six local secondaries are beamed live into the university's science education lecture theatre two or three times a day, complete with a feed from the classroom's interactive whiteboard.
Meticulous planning means the lecturers know exactly what the teacher will cover in each lesson, and the teachers know how their lesson fits into the trainees' course. Mike sets the scene, makes connections between the lesson and the underpinning theory and alerts trainees to things they may not have spotted.
It is a flexible teaching tool. A discussion about lesson starters can include looking at up to six, from different schools, all in real time. And later, the trainees can ask the teacher why they handled the lesson in a particular way.
Dawn Perry, acting head of science at Peacehaven, who did her PGCE in the school, is enthusiastic. "We have got an open-door policy here so we are all used to being observed and I am quite confident.
"A girl walked out of one of the first lessons I taught with the trainees watching. That wouldn't happen in a training video, but it's the sort of thing they all want to know about. And they saw how I got her back in and carried on with the lesson.
"It's hard when you are observing lessons to start with. You don't know what to look for. Having someone telling you how to observe as you do it has real benefits."
Dawn is now looking forward to schools being able to watch each others'
lessons for their professional development, and experienced teachers being able to help colleagues with difficulties in a particular lesson without changing the dynamic by sitting at the back.
The Teacher Development Agency is now interested and initial evaluations are positive. James Williams, an assistant project director on the In School Teacher Education Programme, says trainees are benefiting from watching excellent lessons in a more structured programme with an accompanying expert commentary.
Teachers, meanwhile, are staying on top of their game because they are constantly revising the underlying theory, while planning the best possible lessons, so benefiting pupils and students.
From next year teachers will be able to record their lessons, but heads are barred from using them to monitor performance. Data protection is among the reasons why the university does not record lessons.
Funding constraints, because the Gatsby foundation grant is conditional on its use in science education, means more money is needed for expansion, even to the other teacher training courses in Sussex. But schools and universities are keen to get their hands on the system.
James is adamant that it creates better teachers than any traditional methods, including on-the-job training schemes.
He says: "You can take anybody off the street and make them look like a teacher, sound like a teacher, and behave like a teacher, but they won't be a teacher because they won't understand why they're doing what they're doing.
"This is where the link with the theory and the practice comes in"