Final answer:
A sample is the small group that pollsters use to make inferences about the opinion of the entire population. The accuracy of a poll depends on whether the sample is representative and is achieved through random sampling. Sample sizes can vary, with typical political polls using 1,000 to 2,000 respondents.
Step-by-step explanation:
The small group that pollsters use to make inferences about the opinion of the whole population is called a sample. Getting the right sample is critical to the accuracy of any poll because it must represent the population effectively. A random sample is used to ensure that every person in the population has the same chance of being chosen, which allows the results to reflect the opinion of the entire population reliably. The success of a study largely depends on how well the population is represented by the sample. To achieve this, probability sampling is often employed, where researchers randomly select participants to be a part of the study, ensuring each individual in the population has an equal opportunity to be included in the sample.
For political polling, especially significant events such as presidential elections, the sample size typically ranges from 1,000 to 2,000 respondents. The objective is to make the sample as representative as possible. Therefore, pollsters such as Gallup, Rasmussen Reports, and the Pew Research Center will choose their sample sizes based on the desired accuracy and representativeness of the poll. Moreover, as societal and technological shifts occur, so do the methods of polling, with an increase in Internet-based surveys and automated systems.