eitodennäköisyys

Eitodennäköisyys, sometimes translated as "counter-probability" or "unlikelihood," is a term used in discussions about probability and statistical inference. It refers to the probability of an event occurring given that certain conditions are met, but with a specific focus on ruling out alternative explanations or hypotheses. This concept is closely related to Bayesian inference, where prior beliefs are updated based on new evidence.

In essence, eitodennäköisyys seeks to quantify the probability of an observation under a null hypothesis, contrasting it with the probability of the same observation under an alternative hypothesis. For example, when testing a new drug, one might calculate the eitodennäköisyys of observing a positive patient outcome if the drug had no effect (the null hypothesis), compared to the probability if the drug is indeed effective (the alternative hypothesis). A low eitodennäköisyys under the null hypothesis suggests that the observed outcome is unlikely to have occurred by chance alone, thus providing evidence for the alternative hypothesis.

The term is not as widely established as standard probability terms like "likelihood" or "posterior probability" and can sometimes be a source of confusion. However, it highlights the importance of considering what is *not* happening or what is *not* true when evaluating the strength of evidence. Understanding eitodennäköisyys requires a solid grasp of conditional probability and hypothesis testing frameworks.