Measuring sexual behaviours and attitudes in hard-to-reach groups. A comparison of a non-probability web survey with a national probability sample survey

Couper, Mick P; Conrad, Frederick G; Geary, Rebecca S; Erens, Bob; Copas, Andrew J; Burkill, Sarah; Sonnenberg, Pam; Mercer, Catherine H. (2019). Measuring sexual behaviours and attitudes in hard-to-reach groups. A comparison of a non-probability web survey with a national probability sample survey. Survey Methods: Insights from the Field (SMIF).