CS CS Artificial Intelligence & Machine Learning 2

Question 1

What does 'overfitting' mean in the context of machine learning models?

Accepted Answer

The model performs well on training data but poorly on unseen test data

Answer

Overfitting occurs when a model memorizes training data noise rather than generalizing patterns, resulting in poor performance on new data.

Question 2

Which activation function is most commonly used in hidden layers of modern deep neural networks?

Accepted Answer

ReLU

Answer

ReLU (Rectified Linear Unit) is widely used in hidden layers because it is computationally efficient and mitigates the vanishing gradient problem.

Question 3

What technique is used in random forests to create diversity among individual decision trees?

Accepted Answer

Bootstrap aggregating (bagging) with random feature subsets

Answer

Random forests use bagging to train each tree on a random bootstrap sample and also randomly select a subset of features at each split, creating diverse trees.

Question 4

In natural language processing, what does TF-IDF stand for?

Accepted Answer

Term Frequency - Inverse Document Frequency

Answer

TF-IDF (Term Frequency–Inverse Document Frequency) weighs terms by how often they appear in a document relative to how rare they are across all documents.

Question 5

What is the primary purpose of cross-validation in machine learning?

Accepted Answer

To evaluate model generalization by testing on multiple held-out data splits

Answer

Cross-validation estimates how well a model generalizes by repeatedly splitting the dataset into training and validation subsets and averaging performance across splits.

(CS) Computer Science Practice Test

(CS) Computer Science Practice Test

CS CS Artificial Intelligence & Machine Learning 2