Persistence arc - A persistence arc is a directed connection from a variable at one time step to its copy at a later step in a dynamic Bayesian network.
Perspective projection - Perspective projection maps a three-dimensional point to a two-dimensional image through a camera center.
Pessimistic description - A pessimistic description is a conservative description of a high-level action in angelic hierarchical planning.
Phoneme - A phoneme is a contrastive sound category in a language: replacing it with another phoneme can distinguish one word from another.
Phrase search - Phrase search retrieves text in which a sequence of query terms occurs with specified positional relationships, usually adjacent and in the same order for...
Phrase structure - Phrase structure is the hierarchical organization of a sentence into constituents, such as noun phrases and verb phrases.
PID controller - A PID controller is a feedback controller that combines proportional, integral and derivative contributions to produce a control command.
Pipeline architecture - Pipeline architecture organizes a system into processing stages whose outputs feed later stages.
Plan recognition - Plan recognition is the task of inferring an agent's possible plans from observations of its behavior and relevant context.
Planar Drawing - A planar drawing represents a graph in the plane with distinct points for vertices and edges that meet only at shared endpoints.
Planarity - Planarity is the property of a graph that allows it to be drawn in a plane without edges crossing, except where they meet at shared endpoints.
Planning graph - A planning graph is a layered data structure that summarizes which facts and actions may become available as a planning problem progresses.
Playout - A playout is a simulated continuation from a game state to an outcome, with moves selected according to a specified policy.
Ply - A ply is one move by a single player in a game, corresponding to one action step down a game tree under the usual convention.
Pointwise product - A pointwise product multiplies corresponding values of functions or arrays.
Policy search - Policy search is a reinforcement-learning approach that improves a decision rule by searching over candidate policies or their parameters.
Polynomial kernel - A polynomial kernel compares two feature vectors by raising a scaled, shifted dot product to an integer power. A common form is K(x, z) = (1 + x dot z)^d.
POMCP - POMCP stands for Partially Observable Monte Carlo Planning.
Pose - Pose is an object's position and orientation relative to a specified reference frame. It describes both where the object is and how it is turned.
Possibility theory - Possibility theory is a mathematical framework for representing uncertainty through degrees of possibility and necessity.
Possible world - A possible world is a specified way a situation could be, used to evaluate whether statements are true or false.
Potential field - A potential field is a scalar function over positions or robot configurations that guides motion through its slope.
Precedence constraints - Precedence constraints specify required temporal relationships between tasks. In finish-to-start form, one task must finish before another may begin.
Precomputation - Precomputation means calculating information before the moment it is needed, then storing it for later reuse.
Precondition - A precondition is a condition that must hold for an action to be applicable in a specified model.
Precondition axioms - Precondition axioms are logical statements requiring an action's preconditions to hold whenever that action occurs in a planning model.
Predicate (logic) - In logic, a predicate represents a property of an individual or a relation among individuals.
Predictive learning - Predictive learning, in the world-model sense associated with Yann LeCun, learns from observations to predict aspects of an environment's future state.
Preference constraints - Preference constraints express which assignments are more desirable in a constraint problem, rather than simply declaring which assignments are permitted.
Preference elicitation - Preference elicitation is the process of obtaining information about what a person or group prefers so a system can support decisions on their behalf.
Preference independence - Preference independence, also called preferential independence, means that the ranking of alternatives on a specified set of attributes does not change when...
Prefix - Prefix notation places an operator before its arguments. For example, +(4, 7) expresses the same addition as the infix expression 4 + 7.
Preflow-Push - Preflow-push, also called push-relabel, is an algorithmic approach for finding a maximum flow from a source to a sink in a capacitated network.
Premise - A premise is a statement used as a starting point for reasoning.
Principle of indifference - The principle of indifference assigns equal probabilities to alternatives when the available information provides no reason to favor one over another.
Prioritized circumscription - Prioritized circumscription is a form of nonmonotonic reasoning that assigns precedence to predicates being minimized.
Prioritized sweeping - Prioritized sweeping is a model-based reinforcement-learning and planning technique that concentrates value updates on states likely to be affected by...
Priority queue - A priority queue is a data structure that returns the item with the best priority according to a specified ordering.
Probabilistic context-free grammar - A probabilistic context-free grammar, or PCFG, is a context-free grammar whose production rules have probabilities.
Probabilistic database - A probabilistic database represents uncertainty about database contents using a probability model.
Probabilistic Graphical Model - A probabilistic graphical model represents a probability distribution using a graph and associated numerical functions.
Probabilistic Horn abduction - Probabilistic Horn abduction is a framework that combines logical rules with probabilities assigned to possible hypotheses.
Probabilistic inference - Probabilistic inference is the process of using a probability model to calculate or approximate answers about uncertain quantities.
Probabilistic roadmap - A probabilistic roadmap is a graph built from sampled robot configurations and feasible local paths between them.
Probabilistic semantics - Probabilistic semantics gives a precise probability-based meaning to statements in a knowledge representation system.
Probably approximately correct - Probably approximately correct, usually abbreviated PAC, describes a mathematical learning guarantee.
Problem formulation - Problem formulation is the process of turning a goal into a precise problem that an AI method can solve.