On the question of how many referees are needed to vouch for a job applicant (Letters, 24 January): in my experience, requirements are bizarre and quite illogical.
For example, when I was appointed to my UK chair in medicinal chemistry in 1995, six referees were required, all academic. My previous appointment five years earlier as research director in a French drug company also required six referees, three personal and three professional. A company representative travelled to the UK to interview them in person, visiting London, Cambridge and Glasgow, speaking to each for more than an hour.
In contrast, moving from the UK chair to a senior post with a French multinational cosmetic firm required several visits to Paris for interviews, but no referees at all.
How many referees should be required for a vice-chancellor post? I think between six and eight, half chosen by the candidate and half by the recruiting university. Probably the most concise reference I have ever heard is that given by Nobel prizewinner Sir Derek Barton, who when asked for a reference for one of his junior colleagues replied as follows: "Take this man above all others."
David Billington, Executive director, Great Western Research, University of Exeter.