ISYE 6501 UPDATED TEST PAPER QUESTIONS AND
ANSWERS SET A+
✔✔Binary variable - ✔✔Variable that can take just two values: 0 and 1.
✔✔Box and whisker plot - ✔✔Graphical 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 - ✔✔Transformation of a non-normally-distributed response
to a normal distribution.
✔✔CART - ✔✔Classification and regression trees.
✔✔Categorical data - ✔✔Data that classifies observations without quantitative meaning
(for example, colors of cars) or where quantitative amounts are categorized(for
example, "0-10, 11-20, ...").
✔✔Causation - ✔✔Relationship in which one thing makes another happen (i.e., one
thing causes another).
✔✔Change detection - ✔✔Identifying when a significant change has taken place in a
process.
✔✔Classification - ✔✔The separation of data into two or more categories, or (a point's
classification) the category a data point is put into.
✔✔Classification tree - ✔✔Tree-based method for classification. After branching to split
the data, each subset is analyzed with its own classification model.
✔✔Classifier - ✔✔A boundary that separates the data into two or more categories. Also
(more generally) an algorithm that performs classification.
,✔✔Cluster - ✔✔A group of points identified as near/similar to each other.
✔✔Cluster center - ✔✔In some clustering algorithms (like 𝑘𝑘-means clustering), the
central point (often the centroid) of a cluster of data points.
✔✔Clustering - ✔✔Separation of data points into groups ("clusters")
✔✔Collective outlier - ✔✔A set of data points that is (uncommonly) different from others
- for example, a missing heartbeat in an electrocardiogram
✔✔Concave function - ✔✔A function where the values are always above [or equal to]
the function's Line between end points.
✔✔Concordance index - ✔✔Area under the ROC curve; an estimate of the classification
model's accuracy. Also called AUC.
✔✔Confusion matrix - ✔✔Visualization of classification model performance.
✔✔Constant - ✔✔A number that remains the same.
✔✔Constraint - ✔✔Part of an optimization model that describes a restriction on the
solution (the values of the variables).
✔✔Contextual outlier - ✔✔A data point that is (uncommonly) far from other data points
related to it
✔✔Convex function - ✔✔A function where the values are always below [or equal to] the
function's Line between end points..
✔✔Convex hull (of a set of points) Smallest convex shape that the set of points is
contained in. - ✔✔
✔✔Corrected AIC - ✔✔Improved version of AIC, especially when sample size is small.
✔✔Correlation - ✔✔Relationship in which two things are likely to happen together,
regardless of whether one causes the other.
✔✔Covariate - ✔✔A characteristic or measurement that can be used to estimate the
value of something.
✔✔Cross-validation - ✔✔Validation technique where a model is tested on data different
from what it was trained on.
, ✔✔CUSUM - ✔✔Change detection method that compares observed distribution mean
with a threshold level of change. Short for "cumulative sum".
✔✔Data point - ✔✔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 - ✔✔Choice of action.
✔✔Decision tree - ✔✔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).
✔✔Descriptive analytics - ✔✔Loosely speaking, the use of analytics to explain or
describe what has happened.
✔✔Detrending - ✔✔Removal of trend, such as a change in the mean over time, from
timeseries data.
✔✔Differencing - ✔✔Using the difference of successive values in time series data,
rather than the values themselves. Sometimes nonstationary data will have stationary
differences.
✔✔Dimension - ✔✔A feature of the data points (for example, height or credit score).
✔✔Distance - ✔✔How far it is between two points -- but there are different ways to
measure it (see Minkowski distance).
✔✔Distribution-fitting - ✔✔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 - ✔✔Two-parameter exponential smoothing
technique that incorporates trend.
✔✔Earth - ✔✔Name of many implementations of multi-adaptive regression spline
(MARS) model, because "MARS" is a trademark.
✔✔Eigenvalue - ✔✔Amount by which an eigenvector gets rescaled in a linear
transformation.
✔✔Eigenvector - ✔✔Non-zero vector that does not change direction when a linear
transformation is applied to it, but only gets rescaled by the eigenvalue
✔✔Elastic net - ✔✔Combination of lasso and ridge regression.
ANSWERS SET A+
✔✔Binary variable - ✔✔Variable that can take just two values: 0 and 1.
✔✔Box and whisker plot - ✔✔Graphical 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 - ✔✔Transformation of a non-normally-distributed response
to a normal distribution.
✔✔CART - ✔✔Classification and regression trees.
✔✔Categorical data - ✔✔Data that classifies observations without quantitative meaning
(for example, colors of cars) or where quantitative amounts are categorized(for
example, "0-10, 11-20, ...").
✔✔Causation - ✔✔Relationship in which one thing makes another happen (i.e., one
thing causes another).
✔✔Change detection - ✔✔Identifying when a significant change has taken place in a
process.
✔✔Classification - ✔✔The separation of data into two or more categories, or (a point's
classification) the category a data point is put into.
✔✔Classification tree - ✔✔Tree-based method for classification. After branching to split
the data, each subset is analyzed with its own classification model.
✔✔Classifier - ✔✔A boundary that separates the data into two or more categories. Also
(more generally) an algorithm that performs classification.
,✔✔Cluster - ✔✔A group of points identified as near/similar to each other.
✔✔Cluster center - ✔✔In some clustering algorithms (like 𝑘𝑘-means clustering), the
central point (often the centroid) of a cluster of data points.
✔✔Clustering - ✔✔Separation of data points into groups ("clusters")
✔✔Collective outlier - ✔✔A set of data points that is (uncommonly) different from others
- for example, a missing heartbeat in an electrocardiogram
✔✔Concave function - ✔✔A function where the values are always above [or equal to]
the function's Line between end points.
✔✔Concordance index - ✔✔Area under the ROC curve; an estimate of the classification
model's accuracy. Also called AUC.
✔✔Confusion matrix - ✔✔Visualization of classification model performance.
✔✔Constant - ✔✔A number that remains the same.
✔✔Constraint - ✔✔Part of an optimization model that describes a restriction on the
solution (the values of the variables).
✔✔Contextual outlier - ✔✔A data point that is (uncommonly) far from other data points
related to it
✔✔Convex function - ✔✔A function where the values are always below [or equal to] the
function's Line between end points..
✔✔Convex hull (of a set of points) Smallest convex shape that the set of points is
contained in. - ✔✔
✔✔Corrected AIC - ✔✔Improved version of AIC, especially when sample size is small.
✔✔Correlation - ✔✔Relationship in which two things are likely to happen together,
regardless of whether one causes the other.
✔✔Covariate - ✔✔A characteristic or measurement that can be used to estimate the
value of something.
✔✔Cross-validation - ✔✔Validation technique where a model is tested on data different
from what it was trained on.
, ✔✔CUSUM - ✔✔Change detection method that compares observed distribution mean
with a threshold level of change. Short for "cumulative sum".
✔✔Data point - ✔✔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 - ✔✔Choice of action.
✔✔Decision tree - ✔✔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).
✔✔Descriptive analytics - ✔✔Loosely speaking, the use of analytics to explain or
describe what has happened.
✔✔Detrending - ✔✔Removal of trend, such as a change in the mean over time, from
timeseries data.
✔✔Differencing - ✔✔Using the difference of successive values in time series data,
rather than the values themselves. Sometimes nonstationary data will have stationary
differences.
✔✔Dimension - ✔✔A feature of the data points (for example, height or credit score).
✔✔Distance - ✔✔How far it is between two points -- but there are different ways to
measure it (see Minkowski distance).
✔✔Distribution-fitting - ✔✔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 - ✔✔Two-parameter exponential smoothing
technique that incorporates trend.
✔✔Earth - ✔✔Name of many implementations of multi-adaptive regression spline
(MARS) model, because "MARS" is a trademark.
✔✔Eigenvalue - ✔✔Amount by which an eigenvector gets rescaled in a linear
transformation.
✔✔Eigenvector - ✔✔Non-zero vector that does not change direction when a linear
transformation is applied to it, but only gets rescaled by the eigenvalue
✔✔Elastic net - ✔✔Combination of lasso and ridge regression.
