How do public opinion polls work? You might think that pollsters simply call and contact as many people as possible to find out what they think about a particular issue, but that is not the case at all. When conducting a poll, the polling company selects a small random sample of the population it is attempting to poll. An effort is made to contact as varied a sample as possible in order to best represent the entire population. Naturally, the larger the sample, the more accurate the poll tends to be because it is more representative of the population at large.
In this video they liken the process to a pot of soup. The cook only needs to sample a spoon full in order to tell if the whole pot tastes good. This is somewhat of an over simplification in our opinion. Polling can be very complex. For example, if you only call participants in your poll during the noon hour of the day on weekdays, you are apt to reach mostly housewives or shut ins. Pollsters must be careful to select a truly random sample and that has a great impact on the quality of the poll.