Misclassification bias: diversity in conceptualisations about having 'had sex'.

Sex Health 7(1):31-4 (2010) PMID 20152093

Understanding the signification of the word 'sex' has implications for both medical research and clinical practice. Little is known about how people of varying ages define sex and how situational qualifiers influence definitions across age groups. To our knowledge, this is the first study of a representative sample to assess attitudes about which sexual behaviours constitute having 'had sex' and to examine possible mediating factors (gender, age, giving/receiving stimulation, male ejaculation, female orgasm, condom use or brevity).