During our autumn governors’ meeting, we were talking about the qualities we should look for when appointing new teaching staff. Surprisingly, we differed enormously in our views. “Surely the shortlisting is simple,” one governor said. “After all, we look at a candidate’s qualifications and take it from there, don’t we?” I pointed out that it really wasn’t that simple, remembering a friend who had initially failed his teaching certificate. Within three years he was a deputy; within seven, the head of a sought-after school in Northampton. Now he lectures in education.

My school’s policy for appointing staff is simple but clearly defined. For an important leadership post, the full governing body is involved. For a management post, a section of the governing body will be involved. And for a classroom teacher appointment, the sole responsibility for selecting and interviewing will normally be mine. I like it this way. Although it may seem that I have too much autonomy, the system works well. We have a happy and stable staff, vacancies are rare, and there is a nice mix of younger and more experienced teachers.

Although governors have an important role in decision-making about senior appointments, care needs to be taken if things aren’t to go disastrously wrong. Some years ago, a colleague allowed himself to be persuaded by the local inspector that he should appoint a particular candidate as deputy head. The inspector was equally persuasive with the governing body which thought that, with his experience, he’d know best. The appointment was a disaster and, for the next six years, the teacher upset children, parents and colleagues in equal measure until, to the head’s delight, she opted for early retirement.

There was nobody to complain to, of course. The inspector and most of the governing body had long since moved on. I was in my second year of headship when we appointed a new deputy and, amazingly for an inner-city school, there were nearly 40 applications.

I wasn’t saddled with needless bureaucracy in those days, and I had time to talk to all the applicants and show them round the school. Some were dull. Some talked endlessly about nothing much, and a few seemed very good indeed. We shortlisted seven and, though it was frowned on in those days, I visited everyone on the list.

One teacher shone out from the rest. Her classroom was a revelation and her children a delight because of it. I knew she’d be able to set up the sort of classroom that would be a model for everybody else.

The governors, naturally, hadn’t visited all the candidates and had to base their decision on the interviews. Moreover, their view of what constituted a deputy head was very different from mine. My preferred teacher interviewed well, but another candidate (at the bottom of my list because her classroom was a shambles) put on a real performance. The governors loved it, and said so, virtually demanding that I agree to her appointment. I refused and argued vehemently for 15 minutes. I won, but the school might have been very different now had I bowed to pressure.

Nine years ago, when London schools came under the Inner London Education Authority’s wing, it wasn’t necessary to find a classroom teacher when a vacancy occurred. You simply phoned the local divisional office, and one would be sent from the pool. Looking back, some were just what I wanted and quite a few weren’t, but there was always the nagging suspicion that if you sent somebody unsuitable back, somebody worse would be dispatched.

I remember the woman who was approaching the end of her career and sent to cover my Year 6 vacancy. She intended to commute fro Brighton every day, but the journey took its toll and, by the time she arrived, she was already exhausted. Her Year 6 class, as Year 6 classes do, quickly took advantage of it. By the second week, she’d had enough. She left her class, strode into my room and told me she couldn’t control her class any more. I told her to go home early, have a good weekend, and come back on Monday morning. I explained that I’d teach her class for a whole week and that she should watch and learn.

With hindsight, I’ve often thought how naive I was being. The class behaved beautifully and produced excellent work. When I moved out, they simply took the poor woman to pieces again.

Eventually, I “swapped” her for an Australian teacher at a nearby school, but realised I’d jumped from the frying pan into the fire when she aimed an overhead projector at a whiteboard and made the children copy notes all day. We crawled through the rest of the year, but I sighed with relief when she caught the boat home.

Since we take students from a nearby university, we often fill vacancies with promising youngsters from final teaching practice. Sometimes, however, we have to advertise and venture into the unknown. As the selection of a teacher has been delegated to me, I’ve developed a technique which seems to work well for us, though I’m certain it would be frowned on officially. I read the application forms carefully, sifting the personality that emerges. Is the personal statement full of fashionable phrases, or are there sparks of originality? Has the writer lots of personal interests and a real passion for education?

I assemble a shortlist with my deputy, and we form a mental picture of the finalists. Then we invite them to school for half a day. I note how a candidate comes into my room. Does she (in primary education, it’s usually a she) have a handshake like a wet cod? Does she seem nervous, over-confident, or relaxed but alert? I explain what I’m looking for, and invariably she will comment on our colourful displays of work and welcoming atmosphere.

We talk I a lot I and I gently probe. The literacy hour I does she view it as progress, or a gimmick riddled with pitfalls? What about managing behaviour? Is she in favour of making contracts with children to behave well, or does she think that if you’re an interesting person and a good communicator and you expect children to behave well, they usually will? Then off for a tour of the school. We visit every class and chat to every teacher and assistant. I watch how she interacts with children and, between classrooms, I find out what she can offer the school. Then it’s break time, and I ask her to join the other teachers for a coffee. They’ll talk to her too, and they’ll let me know whether they feel she’s right for our school.

By the time we get back to my room after break, I’ve usually formed a strong opinion. Then, and only then, I look at the candidate’s qualifications, simply because if everything else is right, they usually are as well. When there are two or three really strong candidates, we’ll have a small, informal interview.

It is so important to give an appointment time and care. A teacher could be with a school for years, and if you don’t get it right, you’ll deeply regret it later.

At a coffee break on a course recently, I heard an overbearing teacher proudly telling anybody who’d listen that she’d been promoted and now “had five teachers under her”. Anybody who makes that kind of statement shouldn’t be in a position of management, but I contented myself with remarking that the five teachers must be very uncomfortable. She didn’t understand the joke.

Mike Kent is head of Comber Grove primary, south London. He joins Friday magazine as a columnist this week