posteriorisen

Posteriorisen is a neologism encountered in some discussions of epistemology and information theory to denote either the state of belief after incorporating new evidence or the process by which such a state is reached. The term is not widely standardized and appears primarily in niche or speculative writing.

Origin: formed from the adjective posterior, meaning coming after, combined with the nominal suffix -isen to create a noun for an abstract notion. Its use is informal and not anchored in a formal theory.

In Bayesian terms, posteriorisen can refer to the posterior distribution over hypotheses, or more generally to the act of updating beliefs as data arrive. It emphasizes the end state—the posteriors—rather than the mechanism that generated them.

Some writers employ the term to discuss rational belief revision, arguing that posteriorisen captures the normative content of updating: beliefs should adjust to reflect the strength of evidence while respecting prior information.

Because it remains marginal, there is no consensus on a precise definition, and the term may be used inconsistently across sources. It should be distinguished from established terms such as posterior probability and belief revision.