Probability sampling often strengthens representativeness because selection chances can be described and used in analysis. It does not guarantee success. A well-drawn sample can still suffer if young adults rarely respond, a language group cannot complete the survey, or likely-voter screening excludes eventual participants. Likewise, matching a few census percentages cannot prove that unmeasured political differences disappeared.

The safest interpretation matches the sample to the claim. A carefully weighted sample of registered voters may estimate attitudes among registered voters, not among every resident or among people certain to vote. When an answer choice jumps to a broader population than the study reached, reject it. Representativeness belongs to the relationship between evidence and claim, not to sample size alone.

Video lesson: Science Behind the News: Opinion Polls & Random Sampling