The problems of non-coverage and unlisted numbers in telephone surveys in Britain

SUMMARY The relatively low levels of telephone ownership in Britain, particularly among certain population sub-groups, and the increasing proportion of telephone owners with unlisted ("ex-directory") numbers are two problems which militate against the use of telephone surveys in this country. This paper reviews the nature and extent of these problems and discusses a dual-mode survey approach (using telephone and face-to-face methods) which may provide a viable solution.