Troverdighetsintervallet

Troverdighetsintervallet, or confidence interval in English, is a statistical concept used to express the uncertainty associated with a statistical estimate. When a researcher calculates a statistic from a sample, such as the mean or proportion, it is unlikely to be exactly equal to the true value in the population. A confidence interval provides a range of plausible values for the unknown population parameter.

A confidence interval is typically reported with a confidence level, commonly 95%. This confidence level indicates the long-run proportion of intervals that would contain the true population parameter if the sampling process were repeated many times. For example, a 95% confidence interval for a population mean means that if we were to take 100 different samples and calculate a 95% confidence interval for each, we would expect about 95 of those intervals to capture the true population mean.

The width of a confidence interval is influenced by two main factors: the sample size and the variability of the data. Larger sample sizes generally lead to narrower confidence intervals, indicating greater precision in the estimate. Higher variability in the data, on the other hand, results in wider confidence intervals, reflecting more uncertainty.

Confidence intervals are a crucial tool in statistical inference, allowing researchers to quantify the precision of their estimates and make more informed conclusions about populations based on sample data. They are widely used in various fields, including medicine, social sciences, and engineering.