Convenience sampling

Convenience sampling (also known as grab sampling, accidental sampling, or opportunity sampling) is a type of non-probability sampling that involves the sample being drawn from that part of the population that is close at hand.

Convenience sampling is not often recommended by official statistical agencies for research due to the possibility of sampling error and lack of representation of the population. It can be useful in some situations, for example, where convenience sampling is the only possible option. A trade-off exists between this method's speed and accuracy. Collected samples may not accurately represent the population of interest and can be a source of bias; however, larger sample sizes reduce the likelihood of sampling error occurring.