To better understand the current landscape of commercially available online nonprobability samples, Pew Research Center conducted a study in which an identical questionnaire was administered to nine ...

For decades the gold standard for public opinion surveys has been the probability poll, where a sample of randomly selected adults is polled and results are used to measure public opinion across an ...

With a population of over 40 million users worldwide, a number doubling every year, the internet has become a medium with distinct business opportunities. To academic and commercial researchers, the ...

Statistics are often estimated from a sample rather than from the entire population. If the inclusion probability of the sample is unknown to the researcher, that is, a nonprobability sample, naively ...

Non-probability samples provide a challenging source of information for official statistics, because the data generating mechanism is unknown. Making inference from such samples therefore requires a ...