DAC Machine Learning & Predictive Analytics 3

Question 1

What does the bias-variance tradeoff describe?

Accepted Answer

The balance between underfitting and overfitting errors

Answer

High bias causes underfitting while high variance causes overfitting, and models must balance the two.

Question 2

Which validation approach is most reliable for a small dataset?

Accepted Answer

K-fold cross-validation

Answer

K-fold cross-validation uses all data for both training and validation across folds, maximizing reliability on small samples.

Question 3

A predictive model performs well in testing but degrades over months in production. This is most likely due to what?

Accepted Answer

Data drift

Answer

Data drift occurs when the statistical properties of incoming data change over time, degrading model performance.

Question 4

In logistic regression, what does the output represent?

Accepted Answer

A probability between 0 and 1

Answer

Logistic regression outputs a probability that an observation belongs to the positive class.

Question 5

Which technique addresses severe class imbalance in a training dataset?

Accepted Answer

SMOTE oversampling of the minority class

Answer

SMOTE synthesizes new minority-class examples to balance the classes for training.

Data Analytics Certifications (DAC) Practice Test