This is the survey published as "The Sexual Marital, and Family Relationships of the English Women" (1956) by Eustace Chesser, hence sometimes known as the Chesser Report. Around 6,000 general practitioners were approached: they were invited to distribute a self-administered questionnaire to their patients. 1688 doctors agreed to co-operate, but 190 subsequently refused on seeing the questionnaire. In the event some 1498 doctors received between them about 18,000 questionnaires. The eventual report was based on material derived from 6251 informants of whom 1474 were in the London area. Only 23 per cent of the questionnaires distributed were returned and it has been suggested by Schofield in "The Sexual Behaviour of Young People" that "the sample was over-represented in the higher educational and income groups."