When Martians appear on Earth and you want to show them the teaching world at its most bizarre, try taking them into a school on the day of an interview for a teaching post. Civilised professions might organise their appointments something like this: a discreet first interview, perhaps followed up by a second, more formal occasion. Maybe some negotiation about the terms, then a call or letter, and an offer and an acceptance or a polite “no thank you”. Who else applied? Not a clue.

Schools do it differently. Procedures vary, but the standard format still prevails - all the short-listed candidates turn up at the same time, dressed to kill. Morning tour of the school, with perhaps some informal discussions (don’t believe it - you’re under constant scrutiny), full afternoon of formal interviews, with an on-the-spot decision. Welcome aboard, Ms X, crack open the sherry. Go home the rest of you, and goodbye for ever...

One of the pains of this tragi-comic tradition is that you know, as you slink off home, who got the job. And you can’t see for the life of you why she did. You meet these three or four other hopefuls at 9 o’clock in the morning and, by the time of the decision, you have all bonded and become bosom pals, comrades in adversity. Now you are still pals, except for one, now known as “the successful candidate”. Never mind, you may never see her again, at least not on the interview circuit.

Experienced interview tourists learn to categorise the other candidates at a glance. I offer you my typology of those you may meet on the tour.

Type 1: The Gladiator Larger than life in every respect. Their interview waiting-room technique is designed to make you feel as small and inadequate as possible. They’ve been everywhere, done everything. If you’ve done it too, they’ve done it twice. Rippling muscles, rippling intellect. In fact, everything about them is rippling. My advice is to prick them with a pin and watch them burst. Reassuringly, interview panels often see through the bluster. If they don’t, and the Gladiator gets the job, you simply wouldn’t have been loud or hearty enough for that school.

Type 2: MsMr Bean Unprepossessing of appearance, this candidate is often prematurely written off by the rest on sight. They are taciturn on the tour of the school, muttering occasionally, “Very interesting”. Their gait is unusual; their personal charisma rating seems none too high. But beware - some unlikely characters blossom in the interview situation and many Beans have ended up as front-runners.

Type 3: The Backpacker

This is the wannabe-a-student-forever candidate. They have just returned from doing Peru, not having wanted to settle down after the PGCE course and get a proper job despite their mother’s dearest wishes. They have applied for this job to keep their mother and the student loan company quiet, but secretly have an eye on the Great Barrier Reef before the century is much older. The interview suit is crumpled, as if it had emerged from the backpack to which they became emotionally attached on the Inca trail. The backpacker may be a threat if senior management can see advantages in a short-term appointment.

Type 4: The Internal Candidate This one’s for real, and quite common - the teacher who’s been filling in on a temporary basis and has applied for the longer-term post. When you’re on the walk round the school together, the staff greet him with a warm “Hi Steve” and smile woodenly, or icily, at you. It’s guaranteed to make you mutter darkly: “It’s a stitch-up.” You’re convinced you’re only there for the beer.

The truth is that the internal may have a headstart, but equally he or she may have done enough in the school for senior management to feel that someone else might fit the bill better. Steve’s interview could be more of a courtesy than a real prospect of appointment. So make no assumptions, remind yourself you’re there on your own merits, and go for it. If the internal gets the job, comfort yourself by slinking away from the school muttering “It’s a stitch-up”.

The final act of the tragi-comedy is at least quick when it happens. After the interviews, the wait. After the wait, the denouement - footsteps along the corridor, “The panel would like to see Ms X, please,” then a distant clink of sherry glasses, and the hollow echo of “Welcome aboard, Ms X”.

The rest of the hopefuls are left, for the moment, on their own, wondering what they did wrong. Sometimes cold comfort is offered along the lines of:

“Any one of you could have done this job...” But the stark fact is that most of you aren’t given the chance.

Be philosophical if and when it happens to you - selection processes are highly unscientific and intuitive. In many cases, the panel could have been wrong, but will never know.

I have still heard no better advice for interviews than to be yourself, let your sense of humour show without it being forced or flippant, and say what you believe.

Saying what you think they want to hear is bad news - it may not be what they want anyway and, if it is, you could be unhappy six months down the line implementing policies with which you have no sympathy.

It will pay you in the end to see the comic side of the interview process as well as the tragic. The day will come when the Gladiator, Bean and Backpacker are creeping home without you, and the clink of the glasses is in your honour.

Welcome aboard, successful candidate!

John Trafford is deputy head of the school of education, University of Sheffield, and chair of governors of an infant school