Over the past two years, I have filled in 11 applications, attended six interviews involving a total of 41 candidates, and got nowhere. A simple calculation suggests there are 6.85 candidate interviews per appointment - so the laws of chance are still on my side. Only after my seventh unsuccessful interview should I start to feel unlucky.

But I am forming a sneaking suspicion that interview fields are made up of two kinds of candidates - those who will be successful within one or two attempts, and the rest of us, doomed to pad out shortlists without ever winning the top prize. The Tim Henmans of education appointments.

In the past, when being interviewed for subject-specific posts, I had the advantage of being a physicist. The key question tended to be: “Do you have a pulse?”, after which it was all plain sailing. But even in these days of chronic teacher shortages there is still a wealth of quality applicants at senior management level.

My disappointment is heightened by a growing lack of faith in the selection process. On four out of six occasions I simply have not recognised the person described to me in feedback. I have been told I was “a cold fish”, unenthusiastic, lacking energy or a sense of humour. Interview questions are not the best comic material, nor is it easy to convey the depth of the support and regard of my current colleagues - nurtured over years - with a few moments of bonhomie. I have been told that governors need someone they can warm to - and there lies the rub.

My most repeated mistake has been to assume that the answers to the questions matter. On one telephone feedback session, the man from the education authority seemed to be consulting his notes on my answers for the first time. Eventually I asked him, in exasperation: “Were there any questions I answered badly?”, to be told that I had given model answers to all 17 interview questions, but was still not required for the second day. Apparently I had not smiled enough.

Interview questions are not the test you have to pass - they are the stage on which you must perform. It comes down to fleeting impressions based on an artificial context. For all the scoring systems and person specifications, the decision is made on a gut feeling. I know that an interview should in some ways be a good test of performance under pressure, and that my moaning might seem like sour grapes. But alongside the many competent appointments made this way, there have been some who have blagged their way through interviews with an avuncular style who governors may have warmed to, but who have singularly failed to inspire staff or pupils.

Assessing people by interview is like the question on the old TV panel game Ask the Family, where a familiar object is seen from an unfamiliar angle and the contestants must guess what it is. In each interview there is opportunity to show only a portion of yourself and what you can do and, in my case, the limited views of my professional persona do not add up to someone the panel want to appoint.

One trick must be to portray yourself in miniature - to give, in the time available, a brief glimpse of your intellect, enthusiasm, energy, humour, presence and leadership. Another would be to have only enough personality to fill a half-hour interview anyway.

In my latest interview, I made a conscious effort to address the contradictory messages I have been given in feedback. The result was no more success than in my first interview two years ago.

I returned to school to the surprised looks of staff who have worked with me for seven years and know full well what I am capable of. I approach future applications with an increasing sense of nervousness born not from a lack of confidence - not in myself, but in the process.

I propose a selection process that involves all the shortlisted candidates drawing straws within a few minutes of arrival. Shortest straw gets the post. This will save time, energy and money, and will secure just as high quality appointments as a method based on unreliable impressions.

The writer is a teacher in Kent