ISYE 6501 Final exam Revised Questions And Answers
Verified 100% Correct
concordance index - ANSWER Area under the ROC curve; an estimate of the
classification model's accuracy. Also called AUC.
Confusion matrix - ANSWER Visualization of classification model performance.
Constant - ANSWER A number that remains the same.
constraint - ANSWER Part of an optimization model that describes a restriction on the
solution (the values of the variables).
Contextual outlier - ANSWER A 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 - ANSWER A simulation that models a system continuously,
at every instant of time; continuous-time simulation models are often based on
differential equations.
Control - 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 - ANSWER A function f() where for every two points 𝑥 and 𝑦, 𝑓(𝑐x+
(1−𝑐)𝑦) ≤ 𝑐f(𝑥) + (1−𝑐)𝑓(𝑦) for all 𝑐 between 0 and 1. In two dimensions, this means if the
points (𝑥,𝑓(𝑥)) and (𝑦,𝑓(𝑦)) are connected with a straight line, the line is always above
[or equal to] the function's curve between those two points. If 𝑓() is convex, then −𝑓() is
concave.
Convex Hull (of a set of points) - ANSWER Smallest convex shape that the set of
points is contained in.
Convex Optimization model - ANSWER An 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 - ANSWER A second-order polynomial function that is
convex.
,Convex Quadratic Program - ANSWER A mathematical program where a convex
quadratic function of the variables is minimized, subject to linear constraints.
Convex Set - ANSWER A 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 - ANSWER A game theory setting where the participants
are also working together to achieve some goal, while also competing in some way.
Corrected AIC - ANSWER Improved version of AIC, especially when sample size is
small.
Correlation - ANSWER Relationship 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 - ANSWER A 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 - ANSWER Validation technique where a model is tested on data
different from what it was trained on.
CUSUM - ANSWER Change detection method that compares observed distribution
mean with a threshold level of change.
Data Point - ANSWER Observation/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 - ANSWER Choice of action.
Decision Point - ANSWER Place in a simulation where there is a branch (or decision to
be made or observed).
Decision Tree - ANSWER Tree-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 - ANSWER Neural network-type model with many hidden layers.
, Descriptive Analytics - ANSWER Loosely speaking, the use of analytics to explain or
describe what has happened.
Design of Experiments - ANSWER Choosing a set of tests to be made to find the effect
of input variables on an outcome.
Deterministic Simulation - ANSWER Simulation with no randomness/uncertainty, so
results are the same each run
Detrending - ANSWER Removal of trend, such as a change in the mean over time,
from time-series data.
Diagnostics odds ratio - ANSWER Ratio 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 - ANSWER Classical optimization model for finding the least-costly set of
foods that meets all dietary requirements.
Differencing - ANSWER Using the difference of successive values in time series data,
rather than the values themselves. Sometimes nonstationary data will have stationary
differences.
Dimension - ANSWER A 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 - ANSWER A simulation that models a system that changes
when specific events occur.
Distance - ANSWER How far it is between two points -- but there are different ways to
measure it (see Minkowski distance).
Distribution-fitting - ANSWER Determining 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 - ANSWER Two-parameter exponential smoothing
technique that incorporates trend.
Dynamic programming - ANSWER Optimization approach that involves making a
sequence of decisions over time, based on the current state of a system.
Verified 100% Correct
concordance index - ANSWER Area under the ROC curve; an estimate of the
classification model's accuracy. Also called AUC.
Confusion matrix - ANSWER Visualization of classification model performance.
Constant - ANSWER A number that remains the same.
constraint - ANSWER Part of an optimization model that describes a restriction on the
solution (the values of the variables).
Contextual outlier - ANSWER A 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 - ANSWER A simulation that models a system continuously,
at every instant of time; continuous-time simulation models are often based on
differential equations.
Control - 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 - ANSWER A function f() where for every two points 𝑥 and 𝑦, 𝑓(𝑐x+
(1−𝑐)𝑦) ≤ 𝑐f(𝑥) + (1−𝑐)𝑓(𝑦) for all 𝑐 between 0 and 1. In two dimensions, this means if the
points (𝑥,𝑓(𝑥)) and (𝑦,𝑓(𝑦)) are connected with a straight line, the line is always above
[or equal to] the function's curve between those two points. If 𝑓() is convex, then −𝑓() is
concave.
Convex Hull (of a set of points) - ANSWER Smallest convex shape that the set of
points is contained in.
Convex Optimization model - ANSWER An 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 - ANSWER A second-order polynomial function that is
convex.
,Convex Quadratic Program - ANSWER A mathematical program where a convex
quadratic function of the variables is minimized, subject to linear constraints.
Convex Set - ANSWER A 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 - ANSWER A game theory setting where the participants
are also working together to achieve some goal, while also competing in some way.
Corrected AIC - ANSWER Improved version of AIC, especially when sample size is
small.
Correlation - ANSWER Relationship 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 - ANSWER A 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 - ANSWER Validation technique where a model is tested on data
different from what it was trained on.
CUSUM - ANSWER Change detection method that compares observed distribution
mean with a threshold level of change.
Data Point - ANSWER Observation/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 - ANSWER Choice of action.
Decision Point - ANSWER Place in a simulation where there is a branch (or decision to
be made or observed).
Decision Tree - ANSWER Tree-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 - ANSWER Neural network-type model with many hidden layers.
, Descriptive Analytics - ANSWER Loosely speaking, the use of analytics to explain or
describe what has happened.
Design of Experiments - ANSWER Choosing a set of tests to be made to find the effect
of input variables on an outcome.
Deterministic Simulation - ANSWER Simulation with no randomness/uncertainty, so
results are the same each run
Detrending - ANSWER Removal of trend, such as a change in the mean over time,
from time-series data.
Diagnostics odds ratio - ANSWER Ratio 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 - ANSWER Classical optimization model for finding the least-costly set of
foods that meets all dietary requirements.
Differencing - ANSWER Using the difference of successive values in time series data,
rather than the values themselves. Sometimes nonstationary data will have stationary
differences.
Dimension - ANSWER A 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 - ANSWER A simulation that models a system that changes
when specific events occur.
Distance - ANSWER How far it is between two points -- but there are different ways to
measure it (see Minkowski distance).
Distribution-fitting - ANSWER Determining 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 - ANSWER Two-parameter exponential smoothing
technique that incorporates trend.
Dynamic programming - ANSWER Optimization approach that involves making a
sequence of decisions over time, based on the current state of a system.
