Final answer:
A main disadvantage of cluster sampling is the potential lack of representativeness in the selected sample, which can lead to inaccurate reflection of the entire population's views.
Step-by-step explanation:
One disadvantage of selecting a cluster sample to investigate a superintendent's goal is that the schools in the cluster sample might not be representative of the broader population of seniors. Cluster sampling involves dividing the overall population into clusters, then randomly selecting individuals from within those clusters to participate. If the selected schools have particular characteristics that are not shared across all schools, the results may not provide an accurate reflection of the entire senior population's perspectives.