1-norm - CORRECT ANSWERSimilar to rectilinear distance; measures the straight-line length of a vector from the origin. If z=(z1,z2,...,zm) is a vector in
... [Show More] an m-dimensional space, then it's 1-norm is square root(|๐ง1|+|๐ง2|+โฏ+|๐ง๐| = |๐ง1|+|๐ง2|+โฏ+|๐ง| = ฮฃm over i=1 |๐ง๐|
A/B Testing - CORRECT ANSWERtesting two alternatives to see which one performs better
2-norm - CORRECT ANSWERSimilar to Euclidian distance; measures the straight-line length of a vector from the origin. If z=(z1,z2,...,zm) is a vector in an ๐-dimensional space, then its 2-norm is the same as 1-norm but everything is squared= square root(ฮฃm over i=1 (|๐ง๐|)^2)
Accuracy - CORRECT ANSWERFraction of data points correctly classified by a model; equal to TP+TN / TP+FP+TN+FN
Action - CORRECT ANSWERIn ARENA, something that is done to an entity.
Additive Seasonality - CORRECT ANSWERSeasonal effect that is added to a baseline value (for example, "the temperature in June is 10 degrees above the annual baseline").
Adjusted R-squared - CORRECT ANSWERVariant of R2 that encourages simpler models by penalizing the use of too many variables.
AIC - CORRECT ANSWERAkaike information criterion- Model selection technique that trades off between model fit and model complexity. When comparing models, the model with lower AIC is preferred. Generally penalizes complexity less than BIC.
Algorithm - CORRECT ANSWERStep-by-step procedure designed to carry out a task.
Analysis of Variance/ANOVA - CORRECT ANSWERStatistical method for dividing the variation in observations among different sources.
Approximate dynamic program - CORRECT ANSWERDynamic programming model where the value functions are approximated.
Arc - CORRECT ANSWERConnection between two nodes/vertices in a network. In a network model, there is a variable for each arc, equal to the amount of flow on the arc, and (optionally) a capacity constraint on the arc's flow. Also called an edge.
Area under the curve (AUC) - CORRECT ANSWERArea under the ROC curve; an estimate of the classification model's accuracy. Also called concordance index.
ARIMA - CORRECT ANSWERAutoregressive integrated moving average.
Arrival Rate - CORRECT ANSWERExpected number of arrivals of people, things, etc. per unit time -- for example, the expected number of truck deliveries per hour to a warehouse.
Assignment Problem - CORRECT ANSWERNetwork optimization model with two sets of nodes, that finds the best way to assign each node in one set to each node in the other set.
Attribute - CORRECT ANSWERA characteristic or measurement - for example, a person's height or the color of a car. Generally interchangeable with "feature", and often with "covariate" or "predictor". In the standard tabular format, a column of data.
Autoregression - CORRECT ANSWERRegression technique using past values of time series data as predictors of future values.
Autoregressive integrated moving average (ARIMA) - CORRECT ANSWERTime series model that uses differences between observations when data is nonstationary. Also called Box-Jenkins.
Backward elimination - CORRECT ANSWERVariable selection process that starts with all variables and then iteratively removes the least-immediately-relevant variables from the model.
Balanced Design - CORRECT ANSWERSet of combinations of factor values across multiple factors, that has the same number of runs for all combinations of levels of one or more factors.
Balking - CORRECT ANSWERAn entity arrives to the queue, sees the size of the line (or some other attribute), and decides to leave the system.
Bayes' theorem/Bayes' rule - CORRECT ANSWERFundamental rule of conditional probability: ๐(๐ด|๐ต)=๐(๐ต|๐ด)*๐(๐ด) / ๐(๐ต)
Bayesian Information criterion (BIC) - CORRECT ANSWERModel selection technique that trades off model fit and model complexity. When comparing models, the model with lower BIC is preferred. Generally penalizes complexity more than AIC.
Bayesian Regression - CORRECT ANSWERRegression model that incorporates estimates of how coefficients and error are distributed.
Bellman's Equation - CORRECT ANSWEREquation used in dynamic programming that ensures optimality of a solution.
Bernoulli Distribution - CORRECT ANSWERDiscrete probability distribution where the outcome is binary, either 0 or 1. Often, 1 represents success and 0 represents failure. The probability of the outcome being 1 is ๐ and the probability of outcome being 0 is ๐ = 1โ๐, where ๐ is between 0 and 1.
Bias - CORRECT ANSWERSystematic difference between a true parameter of a population and its estimate.
Binary Data - CORRECT ANSWERData that can take only two different values (true/false, 0/1, black/white, on/off, etc.)
Binary integer program - CORRECT ANSWERInteger program where all variables are binary variables.
Binary Variable - CORRECT ANSWERVariable that can take just two values: 0 and 1.
Binomial Distribution - CORRECT ANSWERDiscrete probability distribution for the exact number of successes, k, out of a total of n iid Bernoulli trials, each with probability p: Pr(๐)= (n over k) p^k(1-p)^n-k
Blocking - CORRECT ANSWERFactor introduced to an experimental design that interacts with the effect of the factors to be studied. The effect of the factors is studied within the same level (block) of the blocking factor.
box and whisker plot - CORRECT ANSWERGraphical representation data showing the middle range of data (the "box"), reasonable ranges of variability ("whiskers"), and points (possible outliers) outside those ranges.
Box-Cox Transformation - CORRECT ANSWERTransformation of a non-normally-distributed response to a normal distribution.
Branching - CORRECT ANSWERSplitting a set of data into two or more subsets, to each be analyzed separately.
CART - CORRECT ANSWERClassification and regression trees.
Categorical Data - CORRECT ANSWERData that classifies observations without quantitative meaning (for example, colors of cars) or where quantitative amounts are categorized (for example, "0-10, 11-20, ...").
Causation - CORRECT ANSWERRelationship in which one thing makes another happen (i.e., one thing causes another).
Chance Constraint - CORRECT ANSWERA probability-based constraint. For example, a standard linear constraint might be ๐ดxโค๐. A similar chance constraint might be Pr (๐ดxโค๐)โฅ0.95
Change Detection - CORRECT ANSWERIdentifying when a significant change has taken place in a process.
Classification - CORRECT ANSWERThe separation of data into two or more categories, or (a point's classification) the category a data point is put into.
Classification tree - CORRECT ANSWERTree-based method for classification. After branching to split the data, each subset is analyzed with its own classification model.
Classifier - CORRECT ANSWERA boundary that separates the data into two or more categories. Also (more generally) an algorithm that performs classification.
Clique - CORRECT ANSWERA set of nodes where each pair is connected by an arc.
Cluster - CORRECT ANSWERA group of points identified as near/similar to each other.
Cluster Center - CORRECT ANSWERIn some clustering algorithms (like ๐๐-means clustering), the central point (often the centroid) of a cluster of data points.
Clustering - CORRECT ANSWERSeparation of data points into groups ("clusters") based on nearness/similarity to each other. A common form of unsupervised learning.
Collective outlier - CORRECT ANSWERA set of data points that is (uncommonly) different from others - for example, a missing heartbeat in an electrocardiogram; we don't know exactly which millisecond it should've happened in, but collectively there's a set of milliseconds that it's missing from.
Concave Function - CORRECT ANSWERA function f() where for every two points ๐ฅ and ๐ฆ, ๐(๐x+ (1โ๐)๐ฆ) โฅ ๐๐(๐ฅ) + (1โ๐)๐(๐ฆ) for all ๐ between 0 and 1. In two dimensions, this means if the points (๐ฅ,๐(๐ฅ)) and (๐ฆ,๐(๐ฆ)) are connected with a straight line, the line is always below [or equal to] the function's curve between those two points. If ๐() is concave, then โ๐() is convex.
concordance index - CORRECT ANSWERArea under the ROC curve; an estimate of the classification model's accuracy. Also called AUC.
Confusion matrix - CORRECT ANSWERVisualization of classification model performance.
Constant - CORRECT ANSWERA number that remains the same.
constraint - CORRECT ANSWERPart of an optimization model that describes a restriction on the solution (the values of the variables).
Contextual outlier - CORRECT ANSWERA data point that is (uncommonly) far from other data points related to it - for example, in Atlanta, a 90-degree (Fahrenheit) day in winter is an outlier, but a 90-degree day in summer is not.
continuous-time simulation - CORRECT ANSWERA simulation that models a system continuously, at every instant of time; continuous-time simulation models are often based on differential equations.
Control - CORRECT ANSWER(1) A variable whose value remains constant for all runs of an experiment, so changes in this variable don't affect the experiment. (2) Design an experiment where some factors ("controls" by definition (1)) are held constant to avoid them affecting the outcome.
Convex function - CORRECT ANSWERA function f() where for every two points ๐ฅ and ๐ฆ, ๐(๐x+ (1โ๐)๐ฆ) โค ๐f(๐ฅ) + (1โ๐)๐(๐ฆ) for all ๐ between 0 and 1. In two dimensions, this means if the points (๐ฅ,๐(๐ฅ)) and (๐ฆ,๐(๐ฆ)) are connected with a straight line, the line is always above [or equal to] the function's curve between those two points. If ๐() is convex, then โ๐() is concave.
Convex Hull (of a set of points) - CORRECT ANSWERSmallest convex shape that the set of points is contained in.
Convex Optimization model - CORRECT ANSWERAn optimization model where the objective function is to minimize a convex function (or maximize a concave function) and the constraints define a convex set of feasible solutions.
Convex Quadratic Function - CORRECT ANSWERA second-order polynomial function that is convex.
Convex Quadratic Program - CORRECT ANSWERA mathematical program where a convex quadratic function of the variables is minimized, subject to linear constraints.
Convex Set - CORRECT ANSWERA set of points for which a straight line drawn between any two points in the set, stays inside the set. A circle is a convex set. A set shaped like the letter "U" is not convex; the line between the two points on top goes outside of the set.
Cooperative Game Theory - CORRECT ANSWERA game theory setting where the participants are also working together to achieve some goal, while also competing in some way.
Corrected AIC - CORRECT ANSWERImproved version of AIC, especially when sample size is small.
Correlation - CORRECT ANSWERRelationship in which two things are likely to happen together, regardless of whether one causes the other. (There is also a quantitative statistical definition measuring the amount of correlation.)
Covariate - CORRECT ANSWERA characteristic or measurement that can be used to estimate the value of something - for example, a person's height or the color of a car. A "feature" or "attribute"; in the standard tabular format, a column of data.
Cross-validation - CORRECT ANSWERValidation technique where a model is tested on data different from what it was trained on.
CUSUM - CORRECT ANSWERChange detection method that compares observed distribution mean with a threshold level of change.
Data Point - CORRECT ANSWERObservation/record of (perhaps multiple) measurements for a single member of a population or data set. In the standard tabular format, a row of data.
Decision - CORRECT ANSWERChoice of action.
Decision Point - CORRECT ANSWERPlace in a simulation where there is a branch (or decision to be made or observed).
Decision Tree - CORRECT ANSWERTree-based method for decision-making. After branching to split the data, each subset is analyzed with its own decision model (or just has its own decision applied).
Deep Learning - CORRECT ANSWERNeural network-type model with many hidden layers.
Descriptive Analytics - CORRECT ANSWERLoosely speaking, the use of analytics to explain or describe what has happened.
Design of Experiments - CORRECT ANSWERChoosing a set of tests to be made to find the effect of input variables on an outcome.
Deterministic Simulation - CORRECT ANSWERSimulation with no randomness/uncertainty, so results are the same each run
Detrending - CORRECT ANSWERRemoval of trend, such as a change in the mean over time, from time-series data.
Diagnostics odds ratio - CORRECT ANSWERRatio of the odds that a data point in a certain category is correctly classified by a model, to the odds that a data point not in that category is incorrectly classified by the model; equal to (TP/FN) / (FP/TN) = (TN*TP) / (FN*FP)
Diet Problem - CORRECT ANSWERClassical optimization model for finding the least-costly set of foods that meets all dietary requirements.
Differencing - CORRECT ANSWERUsing the difference of successive values in time series data, rather than the values themselves. Sometimes nonstationary data will have stationary differences.
Dimension - CORRECT ANSWERA feature of the data points (for example, height or credit score). (Note that there is also a mathematical definition for this word.)
Discrete-event simulation - CORRECT ANSWERA simulation that models a system that changes when specific events occur.
Distance - CORRECT ANSWERHow far it is between two points -- but there are different ways to measure it (see Minkowski distance).
Distribution-fitting - CORRECT ANSWERDetermining whether a set of data seems to follow a certain probability distribution, or determining which of several distributions the data is close to.
Double exponential smoothing - CORRECT ANSWERTwo-parameter exponential smoothing technique that incorporates trend.
Dynamic programming - CORRECT ANSWEROptimization approach that involves making a sequence of decisions over time, based on the current state of a system. [Show Less]