Answer:
B) voluntary response samples, as they are prone to bias and should not be regarded as reliable.
Explanation:
Voluntary response samples should always be regarded as unreliable. In a voluntary response sample, individuals self-select whether or not to participate in a survey or study. This means that participation is based on the individuals' own interest, motivation, or bias, rather than being randomly selected or representative of the population.
Voluntary response samples can lead to biased results because the individuals who choose to participate may have different characteristics or opinions than the broader population. For example, if a survey about a political issue is conducted using a voluntary response sample, individuals with strong opinions or extreme views may be more likely to participate, while those with moderate or opposing views may choose not to participate. This can result in an overrepresentation of certain opinions and an inaccurate reflection of the overall population.
On the other hand, other sample types have more reliable characteristics:
- Cluster samples involve dividing the population into clusters (such as geographical areas) and randomly selecting some clusters to survey. Cluster samples can be reliable if the clusters are representative of the population.
- Simple random samples involve randomly selecting individuals from the entire population, giving every individual an equal chance of being chosen. Simple random samples are considered highly reliable when properly conducted.
- Stratified samples involve dividing the population into subgroups (strata) based on certain characteristics and then randomly selecting individuals from each subgroup. Stratified samples can be reliable if the subgroups are representative and properly chosen.