Artificial Intelligence Machine Learning 2

Question 1

Which algorithm is a non-parametric method that classifies new points based on the majority class of their nearest neighbors?

Accepted Answer

K-Nearest Neighbors

Answer

K-Nearest Neighbors classifies a point by looking at the k closest training examples and using a majority vote.

Question 2

What is cross-validation used for in machine learning?

Accepted Answer

To estimate model performance on unseen data

Answer

Cross-validation partitions data into folds to provide a reliable estimate of how the model generalizes.

Question 3

Which ensemble method builds multiple decision trees and averages their predictions?

Accepted Answer

Random Forest

Answer

Random Forest builds many decision trees using random subsets of data and features, then averages results.

Question 4

What is 'feature engineering' in the machine learning pipeline?

Accepted Answer

Creating or transforming input variables to improve model performance

Answer

Feature engineering involves creating, transforming, or selecting input variables to make patterns easier for a model to learn.

Question 5

Which gradient boosting library is widely used in US industry competitions and known for speed?

Accepted Answer

XGBoost

Answer

XGBoost is an optimized gradient boosting library that is fast, scalable, and popular in competitions like Kaggle.

Artificial Intelligence Practice Test