Data Science FREE Data Science MCQ Question and Answers 2

Question 1

Which technique is used to reduce the number of features in a dataset while preserving most of the variance?

Accepted Answer

Principal Component Analysis

Answer

PCA reduces dimensionality by transforming features into principal components that capture the maximum variance in the data.

Question 2

What does the term 'overfitting' refer to in a machine learning model?

Accepted Answer

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

Answer

Overfitting occurs when a model learns noise in the training data, resulting in poor generalization to new data.

Question 3

In a confusion matrix, what does the 'recall' metric measure?

Accepted Answer

The proportion of actual positives correctly identified

Answer

Recall measures the ability of a model to find all relevant positive instances out of the total actual positives.

Question 4

Which of the following is a supervised learning algorithm?

Accepted Answer

Random Forest

Answer

Random Forest is a supervised ensemble method that uses labeled data to build multiple decision trees for classification or regression.

Question 5

What is the purpose of cross-validation in model evaluation?

Accepted Answer

To estimate how well a model generalizes to independent datasets

Answer

Cross-validation splits data into multiple folds to test model performance across different subsets, providing a robust estimate of generalization.

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