Instrumentation and Measurement:
This is a technique used for collecting data from a sample drawn from a given population.
Survey information is usually obtained through structured interviews or self-administered questionnaires. They can be cross-sectional surveys, where measurements are made at a single point in time, or panel surveys where measurements are acquired at two or more points in time.
Surveys are usually administered on paper, through the mail, in a highly structured interview process (in person or over the phone) in which respondents are asked to choose answers from predetermined choices, or more recently, through electronic mail and online.