There's a strong temptation to shout "Hi-de-hi!" when you meet one of the supervisors at George Green school on London's Isle of Dogs. It's their red uniform that does it - and the fact that they're at work bright and early to cover breakfast club at 7.30am.
"No, it's not Butlin's," says the school's principal, Kenny Frederick. "The red uniform is so that everyone - staff, pupils, parents and carers - knows who they are and what they do. That is, they run the school and allow teachers to teach and pupils to learn."
George Green has 30 teaching assistants in its classrooms, but the supervisors are a rather different species and more corridor-based. The team of 10 women carry walkie-talkies and have been trained in resolving conflict. A major role for both groups at this 1,200-pupil 11-18 secondary school in Tower Hamlets is helping supply teachers. Most of the supervisors are local to the area and they know the children and the school well. "We regularly employ supply staff, and our pupils immediately spot a victim. I sometimes think it must be tattooed on their foreheads and the students set out to test them. This is where our team of supervisors comes in," says Ms Frederick.
"First thing in the morning, they check the rota on the cover board so they can target the classrooms where supply teachers are working, especially at the beginning of lessons. They put their head round the door to introduce themselves to the teacher and to give the kids 'the evil eye'.
"They're making it clear to the pupils and the teacher that they are right outside in the corridor in case assistance is needed, and that they know each and every pupil. It's a comfort to supply staff to know they are not isolated.
"The supervisors in the corridor quickly pick up on any pupil who is disrupting a lesson or failing to co-operate. They've been trained to defuse situations and they are very good at working with even our most difficult pupils.
"They also do the first day of absence calls and deal with all sorts of pastoral care issues. They supervise the toilets, the corridors and playgrounds to make sure that unstructured time is properly managed. They have a set time for debriefing and passing referrals and information on.
"In the classroom, the teaching assistants help the supply teachers settle classes, allowing them to teach. They also know the pupils well and exert a great deal of influence."
The boom in support staff is seen at its clearest in the case of TAs, for whom precise figures are available. Their numbers in England have risen to about 96,000 (full-time equivalent) from just 67,000 in 1997. They are no longer defined by the three Ps: primary, playground and paintpots.
Much of the TA explosion comes down to economics: a school may choose to buy a whole TA rather than a fraction of a teacher. Once you have a sizeable TA workforce, it makes sense, rather than using them as stand-in mums and pencil monitors, to define their roles and have a proper management structure.
That's exactly what has happened at Exmouth community college, a split-site 11-18 secondary school with 2,300 pupils and 24 TAs. The school has five senior TAs, each in charge of four or five assistants, who meet regularly with the school's management. Their teams may be attached to a speciality, such as modern languages or literacy; departmental allowances are traded in to buy TA support.
"A few years ago, we had none," says Hilary Walker, the spokeswoman for Exmouth College. "But the fact is, a school can be better off having four days of a TA who can help for perhaps 13 or 14 lessons than 0.1 or whatever of a teacher. There's a greater variety of TA than you imagine: we have mothers who want a job that fits in with their children's hours, and we have graduates spending a year in school before their PGCE.
"When it comes to the one-to-one work with pupils, the graduates can be great. A disruptive boy who objects to being followed by someone he sees as an old dear responds well to having a young male role model.
"We're a big school in a marine town, so there's quite a lot of coming and going, with children often arriving in the middle of term. We have TAs who are assigned to their induction, who make sure their records are sorted out and that they are settling in.
"Our TAs are familiar with resources, so can often help out a supply teacher. That's another benefit of the team structure, because the TAs know their own area."
How to get the most from your TAs
* What does the TA do? If your support staff have ill-defined duties as "just another pair of hands", resentment and lack of satisfaction could be building up. Review roles and perceptions of roles.
* What isn't being done? If the job isn't defined, unpopular tasks don't get done. Look at what has stacked up by the end of each term and in future allocate it to be done weekly or however often is most efficient.
* What are the TA's strengths and interests? Most TAs and supervisors have had a previous working life and may be able to offer talents the school needs.
* Can you vary the TA's work? You will build up goodwill if you recognise that endless photocopying doesn't lead to alert and loyal members of staff.
* Would everyone benefit if the TA had some training? The answer is almost certainly yes, so check out what's available from your LEA and local colleges and universities.
* Should you be thinking of a separate management structure for TAs and supervisors? Get local heads together for good practice discussions.