Definition: In research, an unobtrusive measure is a method of making observations without the knowledge of those being observed. Unobtrusive measures are designed to minimize a major problem in social research, which is how a subject’s awareness of the research project affects behavior and distorts research results. The main drawback, however, is that there is a very limited range of information that can be gathered this way.

Examples: One way to assess the effect of racial integration in schools is to compare the academic records of students educated in schools whose student populations vary in their degree of racial heterogeneity.