ISYE 6501 Midterm Exam
STUDY GUIDE QUESTIONS
AND VERIFIED CORRECT
ANSWERS GRADED A+ 100%
GUARANTEED PASS [ LATEST
2026-2027]
What is the formula for AIC? - CORRECT ANSWER-AIC=2k - 2*ln(L*) where L* is the maximum
likelihood value and K is the number of parameters estimated.
What is the penality term in AIC and what does it do? - CORRECT ANSWER-2K - It helps prevent
overfitting.
A models that is fit to random effects and not real ones is said to be? - CORRECT ANSWER-
Overfit
What does corrected AIC account for? - CORRECT ANSWER-The fact that we cannot have
infinitely many data points.
If AIC for model 1 is 75 and AIC for model 2 is 80 how do you compute which is better. -
CORRECT ANSWER-It is the relative likelyhood: e^((AIC1-AIC2)/2) = 8.2%
What does BIC stand for? - CORRECT ANSWER-Bayesian Information Criterion
If you have a lot more data than parameters should you use AIC or BIC? - CORRECT ANSWER-BIC
,If you have "fewer" parameters - CORRECT ANSWER-should you use AIC or BIC?, BIC
The "Rule of Thumb" deals with? - CORRECT ANSWER-When comparing two models on the
same data set by their BIC scores.
In exponential smoothing what does alpha do? - CORRECT ANSWER-Adjust the trade off
between current (x_t) and previous values.
In exponential how should you adjust for randomness? - CORRECT ANSWER-Make alpha close
to 0.
In exponential trending, what does Beta do? - CORRECT ANSWER-Adjusts for trending.
In exponential smoothing, what is C_t? - CORRECT ANSWER-A multiplicative seasonality factor
at time t.
In exponential smoothing, what is L? - CORRECT ANSWER-The length of a cycle.
In exponential smoothing, what does gamma do? - CORRECT ANSWER-Adjusts how much cycles
contribute to the model.
In multiplicative seasonality, the first L values of C are set to what? - CORRECT ANSWER-1.
1-norm - CORRECT ANSWER-Similar to rectilinear distance; measures the sum of the lengths of
each dimension
,2-norm - CORRECT ANSWER-Similar to Euclidian distance; measures the straight-line length of a
vector from the origin.
Additive seasonality - CORRECT ANSWER-Seasonal effect that is added to a baseline value.
Adjusted R-squared/Adjusted R2 - CORRECT ANSWER-Variant of R2 that encourages simpler
models by penalizing the use oftoo many variables.
AIC - CORRECT ANSWER-Akaike information criterion
Akaike information criterion - CORRECT ANSWER-Model selection technique that trades off
between model fit and model complexity. Model with lower AIC is preferred. Generally
penalizes complexity less than BIC.
Algorithm - CORRECT ANSWER-Step-by-step procedure designed to carry out a task.
Analysis of Variance/ANOVA - CORRECT ANSWER-Statistical method for dividing the variation in
observations among different sources.
Area under curve/AUC - CORRECT ANSWER-Area under the ROC curve; an estimate of the
classification model's accuracy. Also called concordance index.
ARIMA - CORRECT ANSWER-Autoregressive integrated moving average.
Attribute - CORRECT ANSWER-A characteristic or measurement - for example, a person's height
or the color of a car. Aka "feature", "covariate" or "predictor"
Autoregression - CORRECT ANSWER-Regression technique using past values of time series data
as predictors of future values.
, Autoregressive integrated moving average (ARIMA) - CORRECT ANSWER-Time series model that
uses differences between observations when data is nonstationary. Also called Box-Jenkins.
Bayes' theorem/Bayes' rule - CORRECT ANSWER-Fundamental rule of conditional probability:
𝑃(𝐴|𝐵) = 𝑃(𝐵|𝐴)𝑃(𝐴) / 𝑃(𝐵) .
Bayesian Information criterion - CORRECT ANSWER-(BIC) Model selection technique that trades
off model fit and model complexity. Generally penalizes complexity more than AIC. Lower is
better.
Bayesian regression - CORRECT ANSWER-Regression model that incorporates estimates of how
coefficients and error are distributed.
BIC - CORRECT ANSWER-Bayesian information criterion
Binary data - CORRECT ANSWER-Data that can take only two different values (true/false, 0/1,
black/white, on/off, etc.).
Binary variable - CORRECT ANSWER-Variable that can take just two values: 0 and 1.
Box and whisker plot - CORRECT ANSWER-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 - CORRECT ANSWER-Transformation of a non-normally-distributed
response to a normal distribution.
CART - CORRECT ANSWER-Classification and regression trees.
STUDY GUIDE QUESTIONS
AND VERIFIED CORRECT
ANSWERS GRADED A+ 100%
GUARANTEED PASS [ LATEST
2026-2027]
What is the formula for AIC? - CORRECT ANSWER-AIC=2k - 2*ln(L*) where L* is the maximum
likelihood value and K is the number of parameters estimated.
What is the penality term in AIC and what does it do? - CORRECT ANSWER-2K - It helps prevent
overfitting.
A models that is fit to random effects and not real ones is said to be? - CORRECT ANSWER-
Overfit
What does corrected AIC account for? - CORRECT ANSWER-The fact that we cannot have
infinitely many data points.
If AIC for model 1 is 75 and AIC for model 2 is 80 how do you compute which is better. -
CORRECT ANSWER-It is the relative likelyhood: e^((AIC1-AIC2)/2) = 8.2%
What does BIC stand for? - CORRECT ANSWER-Bayesian Information Criterion
If you have a lot more data than parameters should you use AIC or BIC? - CORRECT ANSWER-BIC
,If you have "fewer" parameters - CORRECT ANSWER-should you use AIC or BIC?, BIC
The "Rule of Thumb" deals with? - CORRECT ANSWER-When comparing two models on the
same data set by their BIC scores.
In exponential smoothing what does alpha do? - CORRECT ANSWER-Adjust the trade off
between current (x_t) and previous values.
In exponential how should you adjust for randomness? - CORRECT ANSWER-Make alpha close
to 0.
In exponential trending, what does Beta do? - CORRECT ANSWER-Adjusts for trending.
In exponential smoothing, what is C_t? - CORRECT ANSWER-A multiplicative seasonality factor
at time t.
In exponential smoothing, what is L? - CORRECT ANSWER-The length of a cycle.
In exponential smoothing, what does gamma do? - CORRECT ANSWER-Adjusts how much cycles
contribute to the model.
In multiplicative seasonality, the first L values of C are set to what? - CORRECT ANSWER-1.
1-norm - CORRECT ANSWER-Similar to rectilinear distance; measures the sum of the lengths of
each dimension
,2-norm - CORRECT ANSWER-Similar to Euclidian distance; measures the straight-line length of a
vector from the origin.
Additive seasonality - CORRECT ANSWER-Seasonal effect that is added to a baseline value.
Adjusted R-squared/Adjusted R2 - CORRECT ANSWER-Variant of R2 that encourages simpler
models by penalizing the use oftoo many variables.
AIC - CORRECT ANSWER-Akaike information criterion
Akaike information criterion - CORRECT ANSWER-Model selection technique that trades off
between model fit and model complexity. Model with lower AIC is preferred. Generally
penalizes complexity less than BIC.
Algorithm - CORRECT ANSWER-Step-by-step procedure designed to carry out a task.
Analysis of Variance/ANOVA - CORRECT ANSWER-Statistical method for dividing the variation in
observations among different sources.
Area under curve/AUC - CORRECT ANSWER-Area under the ROC curve; an estimate of the
classification model's accuracy. Also called concordance index.
ARIMA - CORRECT ANSWER-Autoregressive integrated moving average.
Attribute - CORRECT ANSWER-A characteristic or measurement - for example, a person's height
or the color of a car. Aka "feature", "covariate" or "predictor"
Autoregression - CORRECT ANSWER-Regression technique using past values of time series data
as predictors of future values.
, Autoregressive integrated moving average (ARIMA) - CORRECT ANSWER-Time series model that
uses differences between observations when data is nonstationary. Also called Box-Jenkins.
Bayes' theorem/Bayes' rule - CORRECT ANSWER-Fundamental rule of conditional probability:
𝑃(𝐴|𝐵) = 𝑃(𝐵|𝐴)𝑃(𝐴) / 𝑃(𝐵) .
Bayesian Information criterion - CORRECT ANSWER-(BIC) Model selection technique that trades
off model fit and model complexity. Generally penalizes complexity more than AIC. Lower is
better.
Bayesian regression - CORRECT ANSWER-Regression model that incorporates estimates of how
coefficients and error are distributed.
BIC - CORRECT ANSWER-Bayesian information criterion
Binary data - CORRECT ANSWER-Data that can take only two different values (true/false, 0/1,
black/white, on/off, etc.).
Binary variable - CORRECT ANSWER-Variable that can take just two values: 0 and 1.
Box and whisker plot - CORRECT ANSWER-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 - CORRECT ANSWER-Transformation of a non-normally-distributed
response to a normal distribution.
CART - CORRECT ANSWER-Classification and regression trees.
