Ted Wragg, professor of education at Exeter University, answers your professional problems, big or small, every week. Ask him for independent advice - or offer some of your own - by writing to: Dear Ted, The TES, Admiral House, 66-68 East Smithfield, London E1W 1BX. Or email: email@example.com
It is very tempting to call out: "Oh my God, not you; I might as well go home now," but protocol demands a stiff upper lip in these circumstances.
Even friendly interviews have to be conducted in a slightly formal way, as you are under scrutiny for a job, so you need to be on your best behaviour.
It depends very much on what the interviewer asks you. Most people would be able to behave in a professional way, even if they do not like one of the candidates. If that is the case, then the person should be treated like others on the panel and questions should be answered with due respect.
The real problem arises if you are subjected to hostile questioning, in which case you need to keep your cool. Interviewees sometimes react badly to aggressive questions and either become belligerent themselves or go to pieces. The best strategy is to answer calmly and rationally, and not rise to the bait. That way you will often do yourself a bit of good with the other panel members.
If you feel aggrieved at the outcome, or believe you have been unfairly treated, you can always ring the headteacher for a confidential chat, asking for feedback about your performance. It may be a coded conversation, but it is still one worth having.
As interviews can be quite stressful anyway, even if the panel is thoughtful and kindly, you should not distort, in your own mind, the influence of your "friend". After all, you cannot know whether the other interviewers have a high or low regard for the person, so do not bother guessing.
All this depends, of course, on why the two of you don't get on. A trivial matter may have no effect, but if one of you ran off with the other's spouse, there may be an even bigger problem.
Tell the panel
As a parent-governor, I encountered neighbours and other people I knew several times while I was on interview panels. I would tell the other panel members of my relationship with the applicant and this was taken into account. In any case, the final decision is always a group one, so you would have got the job, or not, on merit.
Barbara Rodgers, Sheffield
Admit knowing the person
The panel member should have told his fellow interviewers during shortlisting that he knew you. If, for some reason - for instance, you had changed your name and he didn't realise he knew you until the interview - he should have declared it then. If he didn't, you should have - when you were introduced you could have smiled and said: "John and I already know each other." If, later, you felt his presence had prejudiced your chances of appointment, you could talk to your union.
However, if you hadn't admitted to knowing him and you were appointed, another candidate could claim prejudice, because you knew a panel member and neither of you had declared it. If you no longer wanted the job because of the person's involvement, you should have told the panel that you had changed your mind, and privately told the chair why you had withdrawn without naming names.
Liz Parkinson, Stockport, Cheshire
There could be some prejudice
Suddenly discovering that the member of an interviewing panel is someone you know dictates only one course of action - tell them. It would depend on that person's role on the panel as to whether you could ask that they step down. If they didn't like you, they may be prejudiced against you. If they did like you, they may compensate by being a bit tougher so they couldn't be accused of favouritism. Letting the panel know of the relationship gives you the best chance of getting a fair hearing, as everyone will be bending over backwards trying to be fair.
Mike Todd, York
Rely on member's professionalism
I'm not sure there's much you could have done on the spot. There is always the hope that the interviewer would declare a "prejudicial interest" and withdraw (and may have done so when the panel went into its deliberation).
However, everyone would have had full details of those attending for interview in advance, so if a prejudicial interest was to be declared, it should have been done before you entered the room.
This person's professionalism or training might stop personal feelings intruding and affecting the outcome of the selection process. After all, it should simply be a matter of applying the "person specification" objectively to each candidate. Plus, other panel members might have the wit and ability to discern and filter one panel member's prejudicial view from their final decision. Even better (from your point of view) they might feel the need, in the name of natural justice, to over-compensate in your favour.
M Thomas, Peacehaven, East Sussex
Complain as a last resort
The best course of action when you know someone on the panel is to carry on with the interview to the best of your ability, answering honestly and stating your opinions concisely and clearly. If the interview doesn't go well, complain to the chairman.
Julia Matthews, Kent
Coming up: Should governors observe?
"I'm a primary head, and some of my governors say they want to do formal observations of my staff. What should I do?" What do readers think? Let us know by emailing firstname.lastname@example.org. We pay pound;40 for every answer published