Which term describes a sampling method that results in an unrepresentative sample?

Sampling bias refers to a systematic error that occurs when a sample is not representative of the population from which it is drawn. This can happen when certain individuals or groups within the population are overrepresented or underrepresented in the sample selection process. For example, if a survey aimed at understanding student opinions only includes responses from a specific class or demographic, it may not reflect the views of the entire student body.

In the context of the other terms, random sampling aims for every individual in a population to have an equal chance of being selected, making it a method generally considered to produce representative samples. Stratified sampling involves dividing the population into subgroups and then sampling from each subgroup, which ideally enhances representation. Systematic sampling selects every nth individual from a population list, which can be representative if the list is randomized but is still structured. In contrast, sampling bias directly denotes the lack of representativeness, making it the correct choice for this question.