What is the main purpose of a confidence interval?

The main purpose of a confidence interval is to provide a range within which a population parameter is expected to lie, based on sample data. It reflects the uncertainty associated with estimating that parameter and offers a way for researchers to quantify the reliability of their estimates. A confidence interval is constructed to give a specified level of confidence (often 95% or 99%) that the interval contains the true parameter, making it a practical tool in statistical analysis to capture the variability and potential error inherent in sample data.

This approach allows researchers to communicate not just a single estimate, but rather the range of values that is plausible, taking into account sample variability. In summary, the confidence interval serves as a crucial framework for interpreting the results of sampling in statistics, emphasizing the importance of acknowledging uncertainty in estimations.