The term "confidence level" refers to a statistical measure that indicates the degree of certainty or accuracy in a sample survey, estimate, prediction or decision. It is usually expressed as a percentage and represents the probability that the results of an analysis will fall within a specified range. In other words, it tells us how confident we can be that our conclusions are accurate.
For example, if a poll has a 95% confidence level, it means that there is a 95% chance that the true percentage for the population would fall within the margin of error (usually around 3%) of the results obtained from the sample surveyed. In other words, we can be 95% confident that our poll results are accurate and representative of the larger population.
The confidence level is determined by considering factors such as the size of the sample, the sampling method used, and the margin of error desired. Generally speaking, a higher confidence level requires a larger sample size to achieve the same degree of accuracy.