Tags
A tag is a keyword or label that categorizes your question with other, similar questions. Using the right tags makes it easier for others to find and answer your question.
Gradient descent is a first-order iterative optimization algorithm. To find a local minimum of a function using gradient descent, one takes steps proportional to the negative of the gradient (or of th…
996 questions
Count data are non-negative integers representing whole amounts.
993 questions
Effect size is "a measure of the strength of a phenomenon or a sample-based estimate of that quantity" [Wikipedia].
985 questions
A discrete, univariate distribution modelling the number of ${\rm Bernoulli}(p)$ trial successes until a specified number of failures occur.
982 questions
A non-negative continuous probability distribution indexed by two strictly positive parameters.
959 questions
A conditional expectation is the expectation of a random variable, given information on another variable or variables (mostly, by specifying their value).
950 questions
An unambiguous list of computational steps involved in finding a solution to a class of problems.
949 questions
A model for time series in which the conditional variance is time-varying and autocorrelated.
944 questions
A matrix (plural matrices) is a rectangular array of numbers, symbols, or expressions arranged in rows and columns. The individual items in a matrix are called its elements or entries.
937 questions
Receiver Operating Characteristic, also known as the ROC curve, is a graphical plot that illustrates the diagnostic ability of a binary classifier system at different thresholds
930 questions
The quantiles of a distribution refer to points on its cumulative distribution function. Some common quantiles are quartiles and percentiles.
924 questions
The Wilcoxon rank sum test, also known as Mann-Whitney U test, is a non-parametric rank test to assess whether one of two samples has larger values than the other.
893 questions
A rule for calculating an estimate of a given quantity based on observed data [Wikipedia].
892 questions
Asymptotic theory studies the properties of estimators and test statistics when the sample size approaches infinity.
883 questions
The field of study concerning statistical methods that use space and spatial relationships (such as distance, area, volume, length, height, orientation, centrality and/or other spatial characteristics…
881 questions
The process of assessing whether the results of an analysis are likely to hold outside of the original research setting. DO NOT use this tag for discussing 'validity' of a measurement or instrument (s…
880 questions
Joint probability distribution of several random variables gives the probability that all of them simultaneously lie in a particular region.
875 questions
The uniform distribution describes a random variable that is equally likely to take any value in its sample space.
865 questions
For questions about the central limit theorem, which states: "Given certain conditions, the mean of a sufficiently large number of iterates of independent random variables, each with a well-defined me…
856 questions
Vector Auto-Regression, a multivariate time-series model / method. Under VAR, each univariate time-series is a linear combination of its own previous values and the previous values of the other series…
854 questions
Usually refers to "z-standardization" which is shifting and rescaling data to assure they have zero mean and unit variance. Other "standardizations" are possible, too.
851 questions
Representing categorical variables as sets of numerical variables. Necessary in many types of analysis for them to process categorical data. A common example is using a categorical predictor in regres…
846 questions
Accuracy of an estimator is the degree of closeness of the estimates to the true value. For a classifier, accuracy is the proportion of correct classifications. (This second usage is not good practice…
843 questions
The process of fiting some statistical model to a particular set of data. Mostly done on a computer, and using varied numerical methods such as optimization or numerical integration, or simulation.
…
838 questions
A multivariate, discrete probability distribution used to describe the results of a random experiment where each of $n$ outcomes are placed into one of $k$ nominal categories.
831 questions
Seasonality refers to the recurring fluctuation around the mean of a time-series for a given period of time, usually a calendar year.
827 questions
A Long Short Term Memory (LSTM) is a neural network architecture that contains recurrent NN blocks that can remember a value for an arbitrary length of time.
808 questions
Cumulative distribution function. While the PDF gives the probability density of each value of a random variable, the CDF (often denoted $F(x)$) gives the probability that the random variable will be …
805 questions
A regularization method for regression models that shrinks coefficients towards zero.
804 questions
A random variable $X$ is called continuous if its set of possible values is uncountable, and the chance that it takes any particular value is zero ($\text{P}(X = x) = 0$ for every real number $x$). A …
802 questions
Questions that seek a conceptual or non-mathematical understanding of statistics.
802 questions
Often abbreviated DID or DD, this is a technique for inferring causality from observational data. It involves comparing measurements before and after a treatment occurs (hence, the growth rate) in bot…
798 questions
Refers to an estimator of a population parameter that "hits the true value" on average. That is, a function of the observed data $\hat{\theta}$ is an unbiased estimator of a parameter $\theta$ if $E(\…
792 questions
The act of generating a sequence of numbers or symbols randomly, or (almost always) pseudo-randomly; i.e., with lack of any predictability or pattern.
790 questions
A distribution describing the time between events in a Poisson process; a continuous analogue of the geometric distribution.
778 questions
The median is the value below which half the data or probability distribution lies - when the sample size is odd, the median is the 'middle' value of an ordered sample.
777 questions