Abstract
Unobtrusive methods use ways of collecting data that do not involve the direct elicitation of information from research participants. They are useful in situations where it might be dangerous or difficult to question respondents directly or where, for one reason or another, using self-report methods will not yield reliable information. Three main sources of unobtrusive data can be distinguished: traces, documentary records, and direct nonparticipative observation. Each of these is discussed with examples of their use, as is the increasing use of unobtrusive data acquired online. The ethical challenges associated with the use of unobtrusive methods are identified, and the issues involved in their generation are discussed.