Non-existent value - A non-existent value, in the referenced database literature, is a missing-value situation where the relevant value does not exist, rather than merely being...
Non-expansive operator - A non-expansive operator is a mapping that never increases the distance between two inputs, measured using a specified norm or metric.
Non-inferiority study - A non-inferiority study is designed to assess whether a new intervention performs no worse than a comparator by more than a prespecified acceptable margin.
Non-linear editing - Non-linear editing is a video-editing method in which an editor can access and arrange recorded clips in any order on a timeline.
Non-linear estimation - Non-linear estimation is the process of estimating unknown quantities in a model when the parameter relationships or estimation problem require nonlinear...
Non-linear forecasting - Non-linear forecasting uses a model in which the predicted quantity has a nonlinear relationship with relevant inputs, such as past observations, past...
Non-local means (NLM) - Non-local means (NLM) is an image-denoising method that estimates a pixel from a weighted average of other pixels whose surrounding patches look similar.
Non-native speech database - A non-native speech database is an organized collection of recordings from people speaking a language they acquired beyond their first-language background...
Non-Negative Least Squares - Non-negative least squares (NNLS) fits a linear combination to observed data while requiring every fitted coefficient to be zero or positive.
Non-personal data - Non-personal data is information that does not relate to an identified or identifiable individual under the applicable definition of personal data.
Non-photorealistic rendering (NPR) - Non-photorealistic rendering (NPR) is the creation of images whose intended appearance differs from a realistic photograph.
Non-random (non-probability) sample - A non-random, or non-probability, sample is a collection of units selected without a probability sampling design that gives population members known...
Non-randomness - Non-randomness, in the supplied graph-analysis context, is a spectral measure intended to characterize structure in a network relative to a random-graph model.
Non-relational database - A non-relational database primarily organizes and accesses data through models other than the traditional relational table model.
Non-response bias - Non-response bias occurs when people who provide data differ in relevant ways from those invited or eligible to respond who do not.
Non-sampling error - Non-sampling error is error in statistical information arising from sources other than the random variation caused by observing a sample instead of the full...
Non-terminal symbols - Non-terminal symbols are grammar symbols that represent categories or intermediate structures and can be expanded by production rules.
Non-uniform memory access - Non-uniform memory access, or NUMA, is a computer architecture in which the time required to access main memory depends partly on where that memory is...
Noncentered parameterization - A noncentered parameterization expresses a model's latent quantities through standardized auxiliary variables and a transformation, rather than sampling...
Noncentrality parameter - A noncentrality parameter is a parameter that distinguishes a noncentral probability distribution from its central counterpart.
Nondirectional test - A nondirectional test is a statistical hypothesis test designed to detect departures from the null hypothesis in either direction.
Nondiscrimination - Nondiscrimination is the principle that people should not face unjustified disadvantage or exclusion on grounds that should not determine their treatment.
Nonhomogeneous Gaussian regression - Nonhomogeneous Gaussian regression is a statistical method that converts ensemble forecasts into a Gaussian predictive distribution whose mean and variance...
Nonlinear conjugate gradient method - The nonlinear conjugate gradient method is a family of algorithms for minimizing a smooth function by combining the current negative gradient with...
Nonlinear constraints - Nonlinear constraints are restrictions on decision variables that involve relationships beyond linear combinations, such as products of variables, squares...
Nonlinear filter - A nonlinear filter is a signal- or image-processing operation that does not obey the superposition property of a linear filter.
Nonlinear modeling - Nonlinear modeling is the construction and use of models that represent relationships beyond a simple constant-rate, additive response.
Nonlinear regression - Nonlinear regression models the relationship between an outcome and one or more predictors using a function that is nonlinear in at least some unknown...
Nonmetric multidimensional scaling - Nonmetric multidimensional scaling (NMDS) represents objects as points in a low-dimensional space while trying to preserve the ordering of their pairwise...
Nonmonotonicity - Nonmonotonicity is the property of a reasoning system in which adding information can invalidate a previously supported conclusion.
Nonparametric density estimation - Nonparametric density estimation estimates the shape of a probability distribution from observed data without restricting it to a fixed finite-dimensional...
Nonparametric estimator - A nonparametric estimator is a rule for estimating a population quantity without restricting the entire population distribution to a particular...
Nonparametric model - A nonparametric model is a statistical or machine-learning model whose flexibility is not restricted to a fixed finite-dimensional parameterization chosen...
Nonparametric tests - Nonparametric tests are statistical hypothesis tests that avoid specifying a particular parametric distribution for the data, or make relatively limited...
Nonprime attribute - A nonprime attribute is an attribute that belongs to none of a relation schema's candidate keys.
Nonresponse - Nonresponse occurs when information intended to be collected from an eligible unit is not obtained or is incomplete.
Nonresponse error - Nonresponse error is the error in a statistical result attributable to information not being obtained from units or items intended to be observed.
Nonserial dynamic programming - Nonserial dynamic programming is a method for solving structured problems by eliminating variables and storing summaries of their interactions with the...
Nonstationarity - Nonstationarity occurs when the statistical behavior of a process changes with time or another relevant index.
Nonstationary kernel - A nonstationary kernel is a covariance function whose value can change when both inputs are translated by the same amount.
Nontrivial MVD - A nontrivial multivalued dependency, or nontrivial MVD, is a dependency X multidetermines Y on relation schema R for which Y is not a subset of X and X...
Norm - A norm is a mathematical function that assigns a nonnegative size to a vector while satisfying three rules: only the zero vector has size zero, scaling a...
Normal distribution - The normal distribution, also called the Gaussian distribution, is a continuous probability distribution with a symmetric bell-shaped density.
Normal distributions transform - The normal distributions transform, or NDT, represents local groups of spatial points with Gaussian distributions and can use that representation to align...
Normal equations - The normal equations are the linear equations that characterize a least-squares solution.
Normal form - A normal form is a specified set of conditions used to assess the structure of a relational database schema with respect to dependencies and redundancy.