What is the term for the unbiased selection of study units from a larger population such that the sample accurately reflects that population?

The term for the unbiased selection of study units from a larger population where the sample accurately reflects that population is known as a representative sample. This sampling method ensures that each subgroup within the population is adequately represented in the sample, which enhances the generalizability of the findings. By achieving a representative sample, researchers can make inferences about the entire population based on the results from the sample, leading to valid conclusions and meaningful insights.

In contrast, convenience samples are typically selected based on accessibility, which can lead to biases, while purposive samples involve selecting specific individuals based on certain criteria, limiting the diversity of the sample. Cluster samples involve dividing the population into groups (clusters) and then randomly selecting entire clusters, which can also affect the representativeness of the sample. Therefore, the concept of a representative sample stands out as crucial for ensuring that research findings are reliable and applicable to the broader population.