Vahvistusvälikoodit

Vahvistusvälikoodit, or confidence intervals in English, are a statistical concept used to express the amount of uncertainty associated with a statistical estimate. Instead of providing a single point estimate for a population parameter, such as the mean, a confidence interval provides a range of plausible values for that parameter. This range is constructed in such a way that, if the same sampling procedure were repeated many times, a certain percentage of the calculated intervals would contain the true, unknown population parameter.

The most common confidence level is 95%. This means that if we were to repeatedly sample from the same population and calculate a 95% confidence interval for each sample, approximately 95% of those intervals would capture the true population parameter. The remaining 5% would not. It is important to note that a confidence interval does not state the probability that the true parameter falls within a *specific* interval; rather, it refers to the long-run success rate of the method used to construct the intervals.

The width of a confidence interval is influenced by two main factors: the confidence level and the sample size. A higher confidence level (e.g., 99% instead of 95%) will result in a wider interval, reflecting greater certainty. Conversely, a larger sample size generally leads to a narrower interval, as it provides more information about the population and reduces uncertainty. Confidence intervals are a valuable tool for interpreting the precision of statistical estimates and for making informed decisions based on data.