I am now retired from full-time teaching but when I was the head of a sixth form one of my best-received assemblies started with: "When I was in a women's prison..." This opener was guaranteed to wake up the students. I continued: "... teaching French", but at least I had their attention. The "message" - and assemblies, like Radio 4's Thought for the Day, always have to have a message - was that when these sixth-formers later found themselves in a position to employ people, be it in a big corporation or to clean their house, they should never discount those who had "done time".
Teaching in a prison is an eye-opening experience. The women came to my classes not because they wanted to learn French but because "education" was a way of getting out of their cells for a couple of hours. We covered topics such as food, shopping, asking for directions and so on - just in case, as they said with a grin, they ever found themselves on the game in Paris.
However, much of our time was spent chatting and the inmates were only too happy to tell me about themselves. What I learned was that the majority of them were there because, in some way or other, they had been let down or had made stupid, simple mistakes.
My aim that day with the sixth-formers was to encourage the students to look beyond the prison badge.
It is with a great sense of regret that, when I go into schools now, I can see that the lesson of that assembly is not being passed on. Prison is still a stigma that taints a person for life - it is impossible to escape it. The context of a conviction, for men or women, is never considered. It remains a damning label.
What is the job of education if not to impart the skills to look beyond a label, to investigate the deeper story and to make decisions based on fact rather than reputation? I find it so sad that people continue to rely on stereotypes, both as children and in later life, letting down a whole section of society which needs support.
The writer is a teacher from the west of England.