One possible explanation for the variability in estimates across the different nonprobability samples is the range of methods that online sample vendors employ. They differ on recruitment, weighting ...

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 ...

The use of non-probability data as a primary data source in official statistics is currently an active field of research. Without the traditional sampling design, modern machine-learning algorithms ...