The interviewer’s role in Natsal is crucial for its success in several ways. Firstly, from the randomly-selected household the interviewer selects one person – at random – to participate in the survey. This is important as it helps to make the findings broadly representative of the general population.
Research has shown that if a household is asked to select a person themselves then it is quite often the person who most wants to talk about sex that does so. This ‘self-selection’ jeopardises representativeness.
Secondly, the interviewer is trained to encourage people to take part, tailoring reasons for participating to the potential participant to demonstrate the relevance of Natsal to them and emphasising the importance of their participation.
Thirdly, the interviewer builds rapport with the participant by asking them the first set of questions so that when they answer the more sensitive questions in the CASI, halfway through the interview, they feel more confident about the process and the importance of answering questions as honestly and accurately as they can.