"The preparation and fieldwork for the National Survey of Sexual Attitudes and Lifestyles was carried out between 1987-1991. The survey was a combination of a face-to-face interview and self-completion questionnaire and comprised 18,876 individuals aged 16-59 years in Great Britain. The response rate was similar to other sample surveys on less sensitive topics. Women were overrepresented but the distributions of other demographic characteristics were similar to other data sets. The external validity and internal consistency of the data were found to be adequate. The likely sources and effects of bias are discussed."
excerpt