3. We undertook visits to 23 prisons. Of these, 21 formed the basis of our study and two (Feltham and Reading) were used as trials for our proposed methodology. Each visit lasted a day and incorporated semi-structured interviews with key members of staff such as the Governor/Director, Head of Personnel, Head of Regime Monitoring, Controller, and the Compliance Officer. We also met and talked with prisoners and carried out a survey of prison officers. A Prisoner Officers' Association (POA) circular had alerted its members of our visits and so we met with union leaders at the prisons if they so wished.