DSE Supervised Learning: Classification 3

Question 1

In a decision tree, what criterion does the Gini impurity measure?

Accepted Answer

The probability of misclassifying a randomly chosen element

Answer

Gini impurity measures the probability that a randomly selected sample would be incorrectly classified if labeled according to the class distribution in the node.

Question 2

What is the effect of setting a very high value for the regularization parameter C in an SVM?

Accepted Answer

Narrower margin with fewer misclassifications allowed

Answer

A high C value penalizes misclassification heavily, leading to a narrower margin and a model that tries hard to correctly classify all training points (risk of overfitting).

Question 3

Which of the following is an assumption of Gaussian Naive Bayes?

Accepted Answer

Features follow a Gaussian distribution within each class

Answer

Gaussian Naive Bayes assumes continuous features are normally distributed within each class.

Question 4

When using k-Nearest Neighbors for classification, what is the effect of choosing a very large k?

Accepted Answer

The decision boundary becomes smoother and simpler

Answer

Large k values smooth out the decision boundary by averaging over more neighbors, reducing variance but potentially increasing bias.

Question 5

The ROC curve plots which two quantities against each other?

Accepted Answer

True Positive Rate vs. False Positive Rate

Answer

The ROC curve plots the True Positive Rate (sensitivity) on the y-axis against the False Positive Rate (1 - specificity) on the x-axis.

DSE - Data Science Practice Test

DSE - Data Science Practice Test

DSE Supervised Learning: Classification 3