It is important that the survey sample size is considered for statistic where 50% of the population answer both ‘yes’ and ‘no’ as this is when the confidence level is broadest and so provides the general level of accuracy for a sample.
Population Size
The population size refers to the number of people within a group that have a similar characteristic. This could be the total number of people living in a town or the number of people with a more specific attribute such as suffering from a disability or residents from a specific ethnic group. Population size is of greatest importance when the population is relatively small and is known.