But if it is so, it seems reasonable to go on to suggest that because acting contains skills which can be improved by practice, then someone, somewhere, should be giving teachers some help with rehearsing them. Brian Sherratt, head of Great Barr GM School in Birmingham, the biggest comprehensive in the country where novice teachers are particularly well looked after emphasises how important it is for the newly-qualified man or woman to adopt the role of the teacher: "to go in there with the intention of engaging the class, through eye contact, through mannerism, through signalling that you are in control".
Pupils, he believes, are good at "reading" the observable behaviour and attitudes of their teachers. "Many of those who go into teaching are completely unaware of that. We think we're sophisticated because we've been to university, but some of our clients are far more wordly wise than we are. They know very well when the teacher's lost his or her grip, or begun to panic. Equally, they know when the teacher's in control. Why do they go quiet when X walks in but don't take a blind bit of notice of Y?" The idea that teachers should be coached in performance skills is much favoured by Dr Robert Tauber, an American professor of education at Behrend College, Penn State University. Last year he wrote Acting Lessons for Teachers with his colleague Cathy Sargent Mester. effectively it is a plea for coaching in areas such as voice, posture, humour, props, the use of space - with some suggestions as to what the training might contain. Early in the book, the authors reflect on the futility of saying to a nervous student teacher: "Don't worry. Just go in there and be yourself. " The point being that, in the example they had in mind, "Imany of these student teachers, were, in fact, rather boring people."
Thus, they go on to say: "Teachers can enhance their versatility by using the same tools of the trade as performing artists."
Dr Tauber feels strongly that performing skills are under-valued in both initial and in-service teacher training. And yet, as he told me himself, "every time we present our material to an audience, they nod and agree - once they've realised that we're not trying to turn them into Johnny Carson stand-ups. I've been at this for 25 years, and for the life of me I can't see why there is resistance."
His perspective, of course, centres on the United States, where, according to his own observation, teachers and principals are comparatively reserved in manner. "I did see teachers in the UK who appeared to be more confident with music and drama. I saw a head in County Durham who was comfortable just picking up his guitar. It seemed to come so easily to him, and I can't see our principals doing it."
This musical head turned out to be Martin Bennett, head of Woodham Burn Junior School in Newton Aycliffe. What Dr Tauber observed, explains Martin, was morning assembly, where, like many primary heads, he puts on what is effectively a show - "lively music, songs with actions, drama, choral speech - and humour once you know your pupils well".
Dr Tauber may well be right about UK primary assemblies which are lively, more often than not. All the same, there are plenty of people ready to say that classroom performance skills are not well recognised in this country either. Martin Bennett himself sees some students "who are not natural teachers and need a lot of help. It's not to do with their academic skills or their organisation - it's something else".
Chris Caswell, a Warwickshire secondary teacher who has worked on non-verbal communication with students and experienced teachers, recalls how in his own college days, he had to prepare a teaching practice file "which would be examined in minute detail by my tutor. But when it came to my performance I would get some bland comment saying that I related well to the pupils".
Most tellingly of all, perhaps, because of whence it came, was the same comment separately offered by two actors who work as costumed period characters in historic houses. In each case, after telling me of the importance of - in the words of one of them - "making good eye contact with the children, looking intensely and really caring what they say; never patronising", they went on to wonder why some teachers, when they are organising their pupils on arrival, fail to display these same basic techniques.
What can be taught? The two main areas are separate, though related. There is use of the voice, and there is body language and posture - "non-verbal communication". Each has its own centre of interest which is trying to make in-roads into the training of teachers. But it is not yet in the mainstream of any programme of teacher education.
The avowed aim of Roz Comins and Voice Care Network UK, a nationwide federation of voice teachers and therapists, is to get sessions on "use of the voice" into colleges and in-service work. "The minute a teacher puts her foot into the classroom," says Roz Comins, "she's a professional voice user."
Her network is growing all the time and, bit by bit, voice sessions are appearing on teacher training programmes - sometimes as a short optional course, sometimes as a single lecture for all students, occasionally as a more intensive study. The driving force here is that teaching can damage the unprepared voice. "The voice gets too high and too hard, there's hardly any breath and the poor old vocal cords are taking a terrible hacking. You finish up hoarse." (Women teachers, she suggests, often unconsciously force their voices to separate them from the children's voices which they otherwise resemble.) She says an alarming number of teachers damage their voices. Extrapolating from known cases in clinics, she reckons that one teacher in 17 will at some time have a voice problem needing treatment. "A lot of people have quietly taken early retirement. Some have been forced to go because they were away so much."
This, of course, makes it a health and safety issue. In a well-publicised case last year, Merseyside teacher Frances Oldfield, supported by the Professional Association of Teachers, won a claim for a state disablement benefit having permanently damaged her voice in the classroom.
But there is, I suggested to Roz Comins, more to it than that. Good vocal skills, surely, are also part of the performance element of teaching. Roz cheerfully agrees with this, and speaks eloquently about "the rhythm of the language and the structure of what you have to say". She is, though, a pragmatist, well-versed in the art of finding funding for her work. "People can understand it when I say I want you to give me some money because people are losing their voices - as opposed to my asking for money so that teachers can improve their speech. They both matter, though."
That people want what she offers seems beyond doubt. Questionnaire feedback from students shows more than half reporting some sort of vocal problem, and a majority requesting follow-up and individual help.
A centre of expertise in body language seems to lie with a two-person team - teacher and academic - based at the University of Warwick. Dr Sean Neill is a psychologist whose specialty has its roots in the study of animal behaviour. Extending this to humans in the classroom, he has done some telling work, using video and drawings, on the way that teachers and pupils see each other. This includes an analysis of a huge range of visual cues, from the fairly simple and obvious ones such as the "head cock" which a teacher uses to signal sympathetic interest in what a child is saying, to the "barrier signals" - fumbling with clothes, for example - given out by the ineffective teacher (and picked up with gleeful alacrity by their pupils).
His co-worker, Chris Caswell, teaches at Myton School in Warwick and, when he has time, does in-service work on non-verbal communication as well as sessions with Warwick students. With Sean Neill he published in 1993 a highly practical book, Body Language for Competent Teachers. This is perhaps the nearest thing to a UK equivalent of the Tauber and Mester book, and it makes the same sort of plea for teacher trainers to take notice of performance. Their research showed "neither third-year student teachers nor probationary teachers (with a few exceptions) had useful input on non-verbal classroom management skills in their courses".
The aim of trying to tackle body language, Chris Caswell points out, is not to teach a whole range of new skills, but to extend those which teachers already have and to raise awareness of what goes on in the classroom. "Sean tended to look at how teachers signalled their intentions. I looked at pupils receiving the signals of the teachers and signalling their own intentions back."
He has many examples of how this can work. "Very often when a pupil is misbehaving, the inexperienced teacher, having dealt with it, will not pick up that the pupil has broken eye contact, and is signalling awareness of being admonished. The teacher, not having read the acceptance signal, will then go on and deal out extra punishment."
It is this sort of example which enables him to argue that to raise awareness of non-verbal communication is not, in fact, to over-emphasise the authoritarian role of the teacher. "What we are saying is that if you are aware of the dynamics you can avoid being overtly authoritarian and yet retain your authority."
And yet there is at least a hint from teacher education that reluctance to emphasise the centrality of the teacher may be partly responsible for the lack of training in performance skills.
Paul Clarke at the University of London's Institute of Education, for example, suggests that "if you make it sound as if the teacher is an imparter of information, it gives a misleading impression". There is much more to teaching than that. PGCE students expect teaching to be "all about performing" - and need to be disabused of that idea.
Nevertheless, he points out that institute students with obvious problems can and do have remedial help, often with a drama specialist on hand. Similarly, at Bishop Grosseteste College - although principal Leonard Marsh finds it difficult to envisage putting performance skills in a named and regular timetable spot ("taking it out and packaging it won't get us anywhere") - students have explicit and specialist help with such practical challenges as making presentations to parents and governors.
The plain truth seems to be that students and experienced teachers do need help with performance, and appreciate it when it is offered. Chris Caswell, like Roz Comins, reports real enthusiasm from teachers with whom he has worked. "I've had phone calls at home from teachers, including one who was amazed at the effect his efforts were now having on groups he used to be nervous of."
And as he points out,whenever a staff body is asked to prioritise its in-service work "the whole issue of teaching and learning styles is raised over and over again. This is part of that".
Finally, and of most interest to the hard-pressed performers themselves, there is evidence that by having attention paid to their performing skills, teachers not only become more able and more confident, but develop a level of professional detachment which protects them from classroom setbacks.
Professor James Calderhead, at Bath University, who researched this among primary teachers, found that there were two distinct groups - "those who saw teaching as a performance could analyse it objectively: if it went terribly wrong, it was a bad performance. Whereas the others felt threatened by failure - if they had a bad lesson, they wanted to forget about it."Sean Neill made the same point. "If you see what you do as dramatic moves, you can say 'I lost my lines today' rather than 'I, as a person, was totally inadequate'."
This, though, is 1995, the year of unprecedented budget cuts, and perhaps the most downbeat reason for looking at performance is provided by the Warwickshire head who, despairing at his rising class sizes, feels charismatic class control is going to be more and more important in the years to come. "Tomorrow's teachers should be coached in performance skills by whoever directed the chariot race in Ben Hur."
Acting Lessons for Teachers by Robert T. Tauber and Cathy Sargent Mester. Praeger, Westport, Connecticut. ISBN:0275 94823 4; paperback, 0275 94824 2 Body Language for Competent Teachersby Sean Neill and Chris Caswell.Routledge. Pounds 12.99 Voice Care Network UK, 29 Southbank Road, Kenilworth,Warwickshire CV8 1LA