This document discusses various modes of administering survey questionnaires and their advantages and disadvantages. It lists face-to-face interviews, self-completion of paper questionnaires, self-completion on a PDA, self-completion computer-assisted interviews, postal questionnaires, internet questionnaires, and telephone interviews. For each mode, it provides some example advantages and disadvantages in terms of cost, ensuring understanding and completeness, safety, representativeness, and respondent comfort. Face-to-face interviews allow the most support but are the most resource-intensive, while self-administered options are less costly but provide less oversight. Telephone interviews are cheaper than face-to-face but present privacy and sampling challenges.