Data Science Data Science Trivia Question and Answers 3

Question 1

What does the bias-variance tradeoff describe in machine learning?

Accepted Answer

The balance between underfitting and overfitting a model

Answer

The bias-variance tradeoff describes how reducing model bias (underfitting) tends to increase variance (overfitting), and finding the right balance is key to good generalization.

Question 2

Which dimensionality reduction technique finds the directions of maximum variance in data?

Accepted Answer

Principal Component Analysis (PCA)

Answer

PCA identifies the principal components, which are orthogonal axes that capture the maximum variance in the dataset, allowing effective dimensionality reduction.

Question 3

What is a confusion matrix used for?

Accepted Answer

Evaluating classification model performance

Answer

A confusion matrix displays true positives, true negatives, false positives, and false negatives to evaluate how well a classification model performs across all classes.

Question 4

In a random forest algorithm, what technique is used to create diverse decision trees?

Accepted Answer

Bagging with random feature selection

Answer

Random forests use bootstrap aggregating (bagging) combined with random feature selection at each split to build diverse, decorrelated decision trees that collectively reduce overfitting.

Question 5

What does the term 'feature engineering' refer to in data science?

Accepted Answer

Creating new input variables from existing data to improve model performance

Answer

Feature engineering is the process of using domain knowledge to create, transform, or select input variables that help a machine learning model make better predictions.

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Data Science Data Science Trivia Question and Answers 3