Final answer:
Convenience sampling involves selecting participants that are easy to contact and may result in biased data due to a lack of randomization. This differs from methods like random digit dialing, which aim to create a representative sample by giving every individual an equal chance of selection.
Step-by-step explanation:
A convenience sample is made up of people who are easy to contact rather than being randomly selected from a larger population. This non-random method selects individuals that are easily accessible and may result in biased data because they do not necessarily represent the whole population. For instance, surveys conducted through convenience sampling might involve interviewing people who are readily available, like those shopping in a store, rather than using a method that ensures each member of the population has an equal chance of being selected, such as random digit dialing or probability sampling.
One major issue with convenience sampling, when compared to methods that aim for a representative sample, is the presence of selection bias. For example, conducting a survey using landline telephones might skew the results towards older people who are more likely to be home. To obtain more accurate and representative data, researchers may use random sampling, where every person has the same chance of being included, or strive for a demographic distribution that matches the larger population.