e/Unobtrusive research

Information
has gloss	eng: Unobtrusive research (or unobtrusive measures) is a method of data collection used primarily in the social sciences. The term unobtrusive measures was first coined by Webb, Campbell, Schwartz, & Sechrest in a 1966 book titled Unobtrusive methods: Nonreactive research in the social science. They described methodologies which do not involve direct elicitation of data from the research subjects. Unobtrusive measures are contrasted with interviews and questionnaires, in that they try to find indirect ways to obtain the necessary data. The unobtrusive approach often seeks unusual data sources, such as garbage, graffiti and obituaries, as well as more conventional ones such as published statistics.
lexicalization	eng: Unobtrusive research
instance of	c/Research methods