Question

which of these methods is most likely to be biased?

• cluster
• systematic
• simple random
• stratified
• convenience

Explanation:

Define probability sampling methods

Using the Systematic Sampling and Stratified Sampling knowledge points

• Cluster, systematic, simple random, and stratified sampling are all probability sampling methods.
• These methods use randomization to select participants, which helps ensure that every member of the population has a known, non-zero chance of being selected, thereby minimizing selection bias.

Analyze convenience sampling

Using the Convenience Sampling knowledge point

• Convenience sampling is a non-probability sampling method.
• It involves choosing individuals who are easiest to reach or most readily available.
• Because it does not rely on random selection, it is highly susceptible to selection bias and is unlikely to produce a representative sample of the population.

Compare likelihood of bias

• Comparing the methods, probability-based designs (simple random, stratified, cluster, systematic) are structured to avoid systematic bias.
• Non-probability designs (convenience) inherently introduce significant bias because the sample is not representative of the broader population.
• Therefore, convenience sampling is the most likely to be biased.

Answer:

• cluster
• systematic
• simple random
• stratified
• convenience (Correct answer)