A confidence interval is a range of values used to estimate an unknown population parameter, like a mean or proportion. It gives us an idea of how uncertain we are about our estimate. For example, if we say the average height of a group of people is between 5.5 and 6.0 feet with a 95% confidence interval, it means we are 95% sure that the true average height falls within that range. The width of a confidence interval depends on the sample size and variability in the data. A larger sample size usually leads to a narrower interval, indicating more precise estimates. In research, confidence intervals help scientists and statisticians, like Nobel laureates, communicate the reliability of their findings.