Michael Somerton is undoubtedly correct in asserting that "becoming an effective teacher should be seen as a long-term process" ("Qualified expectations", Letters, 8 November). However, this does not need to come to an end at retirement, as he suggests. Surely once a teacher always a teacher, and in my experience, with so many post-retirement opportunities for sharing one's knowledge, often in very different situations from those encountered on campus, there is an ongoing need to develop and update one's skills. The principle of "lifelong learning" should apply as much to teaching as to any endeavour.
Roger Ottewill, Mature postgraduate student, University of Birmingham.