Our third Methods 101 video explores some of the ways that nonprobability surveys differ from traditional probability-based polls. How do pollsters conduct surveys online and what does that mean for ...

Learn how representative samples and random samples differ and why combining them minimizes sampling bias for accurate data.

A behind-the-scenes blog about research methods at Pew Research Center. For our latest findings, visit pewresearch.org. Ask a survey methodologist to explain random sampling, or how non-probability ...

Ali Hussain has a background that consists of a career in finance with large financial institutions and in journalism covering business. Vikki Velasquez is a researcher and writer who has managed, ...

Sampling is the process of creating a small unbiased population to be used in a test or experiment. The sample removes the impractical idea of surveying everyone in a market or a population. Random ...