R-bar-squared (R̄2 ) - R-bar-squared, usually called adjusted R-squared, is a regression fit statistic that modifies ordinary R-squared to account for the model's residual degrees...
R chart - An R chart is a statistical process control chart that tracks the range within successive subgroups of measurements.
R-learning - R-learning is an off-policy reinforcement-learning control method for continuing tasks with an average-reward objective.
R-precision - R-precision is a ranked-retrieval evaluation measure calculated at a cutoff equal to the number of relevant documents for the query.
R-squared - R-squared, or the coefficient of determination, compares a regression model's squared prediction errors with the squared deviations of the observed outcomes...
Rademacher complexity - Rademacher complexity measures how strongly a class of functions can align with independent random positive and negative signs on sampled inputs.
Radial basis function - A radial basis function, or RBF, is a function whose value depends on distance from a center rather than on direction from that center.
Radial Basis Function regression - Radial Basis Function regression is a regression method that predicts a value as a weighted sum of radial basis functions, each one centered on a training...
Radial Basis Network - A radial basis network is a neural network that represents inputs through functions of their distance from selected centers.
Radon transform - The Radon transform represents a function through its integrals over lines.
Rainbow table - A rainbow table is a precomputed structure used to search for inputs that produce specified cryptographic outputs, especially password hashes in unsuitable...
Raleigh plot - A Raleigh plot, in the circular-data sense intended here, displays observations as positions around a circle and often adds their mean direction and mean...
Ramification problem - The ramification problem is the problem of representing and reasoning about the indirect effects of actions.
RAMnets - RAMnets are neural-style pattern-recognition systems built from memory lookup units rather than conventional connections with continuously adjusted...
Ramsey RESET test - The Ramsey RESET test is a regression diagnostic that looks for neglected nonlinear structure by adding functions of the original model's fitted values or...
Rand index - The Rand index is a score between zero and one that measures how much two clusterings of the same items agree, by counting the pairs of items they treat the...
RAND-WALK word embedding model - RAND-WALK is a latent-variable model of word generation that helps explain the structure of word embeddings learned from co-occurrence statistics.
Random Effects Model - A random effects model represents selected differences between groups, people, devices or other units as draws from a shared distribution.
Random error - Random error is the component of an estimate's or measurement's deviation that varies unpredictably across repetitions of a specified process.
Random experiment - A random experiment is a process with an uncertain outcome drawn from a defined set of possible outcomes, called its sample space.
Random feature - A random feature is a component of a representation constructed using sampled parameters rather than learning every transformation parameter from the...
Random forest - A random forest is a prediction model made of many decision trees trained on different random slices of the data, whose answers are combined by voting or...
Random-fuzzy variable - A random-fuzzy variable, in the measurement-uncertainty framework developed by Ferrero and colleagues, represents a measurement result while retaining...
Random geometric graph - A random geometric graph is a probabilistic graph model in which nodes occupy randomly chosen positions in a space and nearby nodes are connected.
Random indexing - Random indexing is a method for building compact vector representations by assigning sparse random vectors to contexts and accumulating those vectors for...
Random marginal totals - Random marginal totals are row or column totals in a contingency table whose values are not fixed by the sampling design and can vary across repeated data...
Random model Anova - A random model ANOVA, more commonly called a random-effects analysis of variance, treats the effects of factor levels as draws from a population of possible...
Random network distillation - Random network distillation (RND) is an exploration method that gives a reinforcement-learning agent an intrinsic reward based on prediction error.
Random neural network - The random neural network is Erol Gelenbe's stochastic neural model in which units hold non-negative integer potentials and exchange excitatory or...
Random optimization - Random optimization is an optimization approach that proposes random changes to a current solution and uses objective evaluations to decide whether to...
Random perturbation - Random perturbation, in statistical disclosure control, deliberately changes data using a random mechanism before release.
Random policy - A random policy is a reinforcement learning action-selection rule that uses chance to choose what the agent does.
Random (probability) sample - A random, or probability, sample is selected through a chance-based design in which every unit in the target population covered by the design has a known...
Random projection - Random projection is a dimensionality-reduction method that maps a feature vector into fewer coordinates using a suitably generated random matrix.
Random-restart hill climbing - Random-restart hill climbing is a local-search strategy that runs hill climbing from several randomly selected starting states.
Random rounding - Random rounding is a statistical disclosure-control technique that replaces a value, often a table count, with a nearby rounding-base value chosen using a...
Random sample consensus - Random sample consensus, usually called RANSAC, is a robust model-fitting method that repeatedly fits candidate models to small random subsets and evaluates...
Random start - A random start is an initial position chosen by a specified random mechanism before a systematic sampling sequence is followed.
Random subspace method - The random subspace method is an ensemble-learning approach in which different models are trained on randomly selected subsets of the available features.
Random surfer model - The random surfer model represents movement through a linked network as a probabilistic process.
Random variable - A random variable is a function that assigns a numerical value to each outcome of a random experiment or other probability model.
Random walk - A random walk is a sequence of states produced by repeatedly making a random step from the current state.
Random-walk Metropolis - Random-walk Metropolis is a Markov chain Monte Carlo algorithm that proposes a new state by adding a random increment to the current state.
Randomization, scientific - Scientific randomization uses an explicit chance mechanism to assign experimental units to treatments, determine run order or select units for observation.
Randomized blocks design - A randomized blocks design groups experimental units into blocks that are similar on an important source of variation, then randomizes treatments within...
Randomized non-comparative trial - A randomized non-comparative trial assigns participants randomly to two or more arms but evaluates each arm separately rather than making a prespecified...
Randomized prior network - A randomized prior network is a randomly initialized neural network whose parameters remain fixed and whose output is added to a trainable model.
Randomized Response - Randomized response is a data-collection technique that deliberately introduces known randomness into individual answers so that researchers can estimate an...