To ensure the accuracy of a research, the sample should be

To ensure accuracy a sample must be representative so that it truly reflects the whole population.

A fixed quota is chosen by the researcher and can bias the sample away from true proportions.

Purposive selection by the researcher introduces personal judgment and reduces representativeness.

An as-small-as-possible sample sacrifices precision and raises sampling error.

Representativeness lets findings from the sample be generalized back to the population.

Randomization and adequate size together strengthen the representativeness of a sample.