Survey is defined as the act of examining a process or questioning a selected sample of individuals to obtain data about a service, product, or process. Data collection surveys collect information from a targeted group of people about their opinions, behavior, or knowledge. Common types of example surveys are written questionnaires, face-to-face or telephone interviews, focus groups, and electronic (e-mail or website) surveys.

Getting information in person may be the most personal approach and most effective way of gaining trust and cooperation from the respondent. It is easier to react to puzzled facial expressions, answer questions, probe for clarification, or redirect responses. Face to face contact is particularly useful to detect respondent discomfort when discussing sensitive issues or attempts to respond in a socially desirable way.