Frequentiststatistik

Frequentiststatistik, also known as frequentist probability, is a dominant interpretation of probability within the field of statistics. This approach defines probability as the long-run frequency of an event occurring in a repeatable experiment. Under the frequentist view, probability is an objective property of the world, not a subjective belief. For example, the probability of a fair coin landing heads is 0.5 because if the coin were flipped an infinite number of times, heads would appear approximately 50% of the time.

Key concepts in frequentist statistics include hypotheses, p-values, and confidence intervals. Hypothesis testing involves formulating a null hypothesis (a statement of no effect or no difference) and an alternative hypothesis. The p-value represents the probability of observing data as extreme as, or more extreme than, the actual observed data, assuming the null hypothesis is true. A small p-value suggests evidence against the null hypothesis. Confidence intervals provide a range of plausible values for an unknown population parameter, based on sample data. A 95% confidence interval means that if the same sampling procedure were repeated many times, 95% of the calculated intervals would contain the true population parameter.

Frequentist methods are widely used in scientific research, economics, and engineering due to their emphasis on empirical evidence and objective inference. Critics sometimes point to the difficulty of interpreting probabilities of singular events or the potential for misinterpretation of p-values and confidence intervals. Nevertheless, frequentist statistics remains a foundational framework for statistical analysis.