One form of non-probability sampling is convenience sampling, meaning sampling based on accessibility and opportunity. For instance, we can draw our participants from patients at various hospitals.

The other – and arguably the biggest — difference is that the samples for these surveys are selected using so-called non-probability sampling methods. For decades, only probability – or random – ...

Non-probability Sample: A sampling approach that does not confer every population member a known probability of selection, often necessitating additional statistical adjustments.

These results are consistent with the conclusion that non-probability samples yield data that are neither as accurate as nor more accurate than data obtained from probability samples.

This study reports the findings of a comparison between different non-probability sampling methods applied in a WWW-user-survey.