Dictionary / Confidence level

# Confidence level

Last updated August 16, 2023

## What is a confidence level?

A confidence level (CL) refers to the percentage of probability that the would contain the true population parameter when you draw a random sample many times.

## What is the difference between confidence levels and confidence intervals?

Both statistical concepts are used to describe the accuracy and precision of an estimate. However, a confidence level is the percentage of probability that the confidence interval would contain the true population parameter when you draw a random sample many times.

A confidence interval, on the other hand, is a range of values that is likely to contain the true value of a population parameter with a certain degree of confidence. For example, a 95% confidence interval for the mean weight of a certain population might be from 60kg to 80kg. This means that if the same population was sampled repeatedly, then 95% of the intervals calculated would contain the true mean weight of the population.