Many teachers feel uncomfortable at the prospect and reality of having another adult in the classroom, particularly if the visitor is coming to "observe". Yet classroom observation is an important element of school improvement. Without it, how do senior managers know what is going on and, more importantly, how do teachers get help to develop their skills?
It may be less of an issue for new teachers, who, throughout their training, have been observed, assessed and commented on. but when a head or senior staff member says: "I'd like to come and look at your lesson," most teachers still shudder. Or, if the head walks into their room unannounced, they immediately become defensive.
Why? It is partly a residual view of the professional as master of his or her own classroom; partly the deep insecurity many teachers have about their work, exacerbated in recent years by constant criticism from politicians, media and - the most feared observers of them all - OFSTED inspectors.
But it's an attitude that should be resisted. There's a lot to gain - and very little to lose - from being observed at work. It needs to have a clear purpose. When the observation forms part of an assessment for qualified status or appraisal or inspection, the attitudes of observer and observed will be different from when it is overtly developmental.
It also needs to be focused. Looking at everything that goes on in a classroom - even in just one lesson - is usually unproductive. By concentrating on one aspect, the observer is more likely to produce useful data.
Feedback should be detailed but manageable, and given as soon after the event as possible - waiting to hear the observer's views can be as nerve-racking as the observation itself. And it should be written down, both as a safeguard against misunderstanding and a reminder for the observed.
New teachers in schools that operate under simple rules like these should welcome classroom observation as a stimulus to their own improvement. They can also use it as a lever into the observer's classroom to learn from someone with greater experience.
But formal observations are not the only reason for visiting adults in the classroom. Headteachers often drop in as part of their "management by walking about". Unless you're doing something totally indefensible there's nothing to fear from this sort of visit. It shows that the head is taking an interest in you. It probably means even more if visitors - parents, governors, local worthies and so on - are brought to your room.
But if you get this kind of visit, don't immediately stop what you're doing to greet the visitor - it looks guilty and gives the impression that what you're doing is unimportant. Find a convenient point to greet them but do it quietly - people hate being suddenly incorporated into a lesson, however tempting it may seem to the teacher.
Other adults may spend time in your classroom: teachers with whom you are teamed or non-teaching assistants with responsibility for young people with spec-ial needs. Good planning, a collaborative relationship and the confidence to work effectively with others are vital in both cases. But once these are achieved, the benefits are enormous.
The presence of adult learners can boost "normal age" students' confidence about their education and, for the teacher, be a rich source of interaction.
There is one other group of adults whose presence should be felt in the classroom - parents. They usually take a lot of interest in what goes on, as relayed by their children, and are the silent observers at your shoulder, until something displeases them, when they can become very vociferous. So any time you're tempted to go over the top with a student ask yourself: "Would I do this if his mother was here?" He may be asking himself the same question.
Which suggests another powerful benefit of extra adults in classes: it produces a more civilised atmosphere in which teachers can spend less of their time controlling and more on boosting learning.