Differential privacy - Differential privacy is a mathematical framework for limiting how much the output of an analysis can reveal about the contribution of a particular protected...
Differential return - Differential return is a reward-based quantity used in continuing, average-reward reinforcement learning.
Differential validity - Differential validity concerns whether the relationship between a score or predictor and an intended outcome differs across groups.
Differential value function - A differential value function describes expected future reward relative to a policy's long-run average reward in a continuing task.
Differentially private stochastic gradient descent - Differentially private stochastic gradient descent, or DP-SGD, is a training procedure that limits individual training examples' influence by clipping their...
Diffusion model - A diffusion model is a generative model that learns to produce data through a process related to reversing progressive corruption.
Digidot chart - A digidot chart combines a stem-and-leaf display with a time-order plot of the same numerical observations.
Digit recognition - Digit recognition is the task of identifying digits from an input signal.
Digital continuity - Digital continuity is the ability to keep digital information usable for the purposes and period for which it is needed.
Digital curation - Digital curation is the active management of digital material throughout its lifecycle so that it remains understandable, trustworthy and usable for its...
Digital divide - The digital divide is unequal access to, ability to use, or benefit from digital technologies and information.
Digital elevation map - A digital elevation map is a digital representation of surface elevation across geographic locations, commonly stored as a grid of height values.
Digital geometry - Digital geometry studies the shapes, positions, and geometric properties of objects represented on discrete spaces, such as the grid of pixels in an image...
Digital image - A digital image is a visual representation encoded as data that a computer can store, process, and display.
Digital object memory - A digital object memory is an organized collection of digital information associated with an individual physical object over time.
Digital obsolescence - Digital obsolescence is the loss or weakening of practical access to digital material because the technologies needed to read, interpret or use it are no...
Digital organism - A digital organism is a self-replicating computer program studied in an artificial-life environment where replication, variation and selection can occur.
Digital topology - Digital topology studies connectivity, boundaries, holes, and related structural properties of objects represented on discrete grids.
Digital watermarking - Digital watermarking embeds an identifying or informative signal into digital content so that the signal can later be seen, detected, or recovered.
Digitization - Digitization is converting information from a physical or analog form into a digital representation that a computer can store and process.
Dijkstra's algorithm - Dijkstra's algorithm finds minimum-total-cost paths from a starting node in a weighted graph whose edge weights are nonnegative.
Dimensional fact model - The Dimensional Fact Model, or DFM, is a graphical conceptual model used to design data warehouses.
Dimensionality - Dimensionality is the number of input fields a model must consider at once: one field is one dimension, a spreadsheet with two hundred columns is two...
Dimensionality reduction - Dimensionality reduction represents data using fewer features or coordinates than the original representation.
Dinitz - Dinitz is a maximum-flow algorithm that increases the amount of a single commodity sent from a source to a sink while respecting edge capacities and flow...
Diphthong - A diphthong is a vowel whose quality changes noticeably during its production within a single syllable.
Direct sampling - Direct sampling, in the OECD glossary's survey-statistics sense, means that sampled units are actual members of the population being studied and information...
Direct utility estimation - Direct utility estimation is a reinforcement-learning approach that estimates a state's value by averaging the observed returns following visits to that state.
Direct voice input - Definition: Direct voice input, or DVI, is a human - machine interaction method in which spoken commands provide input to a computer or control interface...
Directed acyclic graph - A directed acyclic graph, or DAG, is a graph whose edges have directions and which contains no directed cycle.
Directed cycle - A directed cycle is a sequence of directed edges that follows their arrow directions and returns to its starting vertex.
Directed graph - A directed graph, also called a digraph, represents objects as nodes and relationships as arrows from one node to another.
Directional arc consistency - Directional arc consistency, or DAC, is a constraint-satisfaction property defined relative to a fixed ordering of variables.
Directional-change intrinsic time - Directional-change intrinsic time is an event-based way to represent a time series in which the clock advances when an observed value reverses from a...
Directional component analysis - Directional component analysis, or DCA, is a statistical method for deriving patterns of variability that reflect a chosen linear impact measure as well as...
Directional derivative - A directional derivative measures the instantaneous rate at which a function changes at a point when its input moves in a specified direction.
Directional test - A directional test is a statistical hypothesis test whose rejection region lies in one specified direction, commonly called a one-sided or one-tailed test.
Directive speech act - A directive speech act is an utterance intended to get another person or system to do something.
Dirichlet boundary condition - A Dirichlet boundary condition specifies the value of an unknown function on a selected boundary of a mathematical domain.
Dirichlet distribution - The Dirichlet distribution is a probability distribution over vectors of proportions that sum to one.
Dirichlet-multinomial model - A Dirichlet-multinomial model combines a Dirichlet distribution over category probabilities with a multinomial distribution over counts.
Dirichlet process - A Dirichlet process is a probability distribution over probability distributions.
Dirty data - Dirty data is an informal name for data with quality problems that make it unreliable or unsuitable for an intended use.
Disambiguation - Disambiguation is the process of determining which interpretation of an expression is intended when more than one is possible.
Discordant pairs - Discordant pairs are pairs of observations whose order is reversed on two variables: the observation with the higher value on one variable has the lower...
Discount - In count-based language modeling, a discount reduces the probability mass assigned to observed events so that some mass can be allocated elsewhere...
Discount factor - A discount factor is a number used to reduce the weight of later rewards relative to earlier rewards in a sequential decision problem.