Survey

A survey is a systematic method for gathering information from a predefined group of respondents to generalize findings to a larger population. Surveys use standardized questions and predefined response options to measure opinions, behaviors, characteristics, or experiences. They are a common tool in social science, market research, public opinion, and program evaluation.

Surveys can be descriptive (describing characteristics of a population), analytical (testing hypotheses), or exploratory (identifying patterns). They may be cross-sectional, collecting data at a single point in time, or longitudinal, following the same respondents over time.

Key elements include the instrument (questionnaire or interview guide), the sampling plan, and the data collection method. Question design involves choosing question types (closed-ended vs open-ended) and scales (nominal, ordinal, interval, ratio). Sampling methods divide into probability-based approaches (random, stratified, cluster) and non-probability approaches (convenience, purposive). Data can be collected online, by telephone, in person, or by mail.

Quality, reliability, and validity are crucial. Researchers address biases such as nonresponse, social desirability, and measurement error, and may apply weighting to adjust for sample demographics. Ethics include informed consent, confidentiality, and data protection.

Surveys have roots in census-taking and opinion research of the 19th and 20th centuries and remain widely used for policy making, product development, and academic study. Limitations include sampling error, nonresponse bias, and the potential for misinterpretation of questions.