This is an example of convenience sampling. Convenience sampling uses subjects that are easily accessible to participate in a study. The student asked 18 friends to participate in a psychology experiment, making them a convenient sample as they were close at hand for the student to recruit. Convenience sampling is a type of nonprobability sampling where accessibility is prioritized over representativeness of the overall population.

1. A student asks 18 friends to participate in a psychology experiment. What kind of sampling
technique is this and why?
Solution
Convenience sampling. Convenience sampling is a type of nonprobability
sampling which involves the sample being drawn from that part of the population which is close
to hand.