Which sampling method is unbiased?

An unbiased sampling method ensures that every individual or item in the population has an equal chance of being selected, thereby producing a sample that is representative of the larger population and minimizing systematic error.

• Random sampling is the correct answer because it involves selecting participants purely by chance, ensuring that each member of the population has an equal and independent probability of being included. This method is fundamental for achieving statistical representativeness and reducing bias.
• Convenience sampling is biased as it selects participants based on their easy accessibility, often leading to a non-representative sample.
• Purposive sampling is also biased because the researcher deliberately chooses participants based on specific characteristics, relying on their judgment.
• Quota sampling, while aiming for specific proportions, is still biased as the selection within those quotas is often non-random and based on convenience.