AIM Framework glossary
Prior
Canonical definition
The Prior, or Prior Probability, is the probability assignment P(H) that the Thinker holds over a Hypothesis H within the representable Hypothesis Space at a given moment of Bayesian Updating, prior to the incorporation of the current Evidence. The Prior is index-relative: each Posterior resulting from an updating cycle becomes the Prior for the next cycle, so “Prior” names a position in the updating chain rather than a privileged absolute starting point. The Prior is the state from which Ground-Resolution, the evaluative operation the Thinker contributes to Conscious Cognition, begins its current redistribution of probability mass across ; it does not in its own right settle whether what the cycle returns amounts to a Belief, which is determined at the moment the updating cycle terminates.
Explanation
A Prior is how plausible your mind currently finds each explanation on its list before taking in the next piece of information. It is not a pristine starting point; it is wherever your thinking engine has already arrived from all the evidence it has processed so far. Every time evidence comes in, the Prior is replaced by an updated distribution, and that updated distribution becomes the new Prior for whatever arrives next. Two features matter: Priors are always there (there is no “neutral” position), and the Prior for a given cycle can itself be a Confabulated output from an earlier cycle, which is why high coupling strength and prolonged closure-demand can bake errors into future updating rather than correct them.
Epistemic status
Inherited (standard Bayesian primitive) with Framework-Specific Integration.
Derivation
Chapter 4, Section 4.3.8; Chapter 4, Section 4.4.3; Chapter 13, Section 13.2.1; Chapter 15, Section 15.2; Chapter 14, Section 14.2.1; Appendix A, Section A.5.6.