You built a model using Lasso regularization but some important features were wrongly set to zero. How would you modify your approach to keep these features?
- Combine with ElasticNet
- Decrease L1 penalty
- Increase L1 penalty
- Switch to Ridge
Combining with ElasticNet allows for balancing between L1 and L2 penalties, thus avoiding complete elimination of important features by the L1 penalty.
If multicollinearity is a concern, ________ regularization can provide a solution by shrinking the coefficients.
- ElasticNet
- Lasso
- Ridge
- nan
Ridge regularization provides a solution to multicollinearity by shrinking the coefficients through the L2 penalty, which helps to stabilize the estimates.
What are some common methods to detect multicollinearity in a dataset?
- Adding more data
- Feature scaling
- Regularization techniques
- VIF, Correlation Matrix
Common methods to detect multicollinearity include calculating the Variance Inflation Factor (VIF) and examining the correlation matrix among variables.
Name a popular algorithm used in classification problems.
- Clustering
- Decision Trees
- Linear Regression
- Principal Component Analysis
Decision Trees are a popular algorithm used in classification problems. They work by recursively partitioning the data into subsets based on feature values, leading to a decision on the class label.
What is regression in the context of Machine Learning?
- A type of classification
- Analyzing computer performance
- Predicting a categorical value
- Predicting a numerical value
Regression in Machine Learning refers to the process of predicting a continuous numerical outcome or dependent variable based on one or more independent variables. It plays a crucial role in various areas, like economics, where it might be used to predict prices, or in biology, to forecast growth rates.
In KNN, how does an increase in the value of K generally affect the bias and variance of the model?
- Decreases bias, increases variance
- Decreases both bias and variance
- Increases bias, decreases variance
- Increases both bias and variance
Increasing the value of K generally increases bias and decreases variance in the KNN model.
You've trained a model with a small training set and a large testing set. What challenges might you encounter, and how could they be addressed?
- Both Overfitting and Underfitting
- Data is perfectly balanced
- Overfitting
- Underfitting
A small training set might lead to overfitting, where the model memorizes noise from the training data. Conversely, it might also lead to underfitting if the model fails to capture the underlying pattern. Cross-validation, bootstrapping, or augmenting the training set with additional relevant data can help balance the model's ability to generalize.
Can you detail how to prevent overfitting in Polynomial Regression?
- By ignoring the test set
- By increasing the degree
- By using all features
- By using regularization techniques like Ridge and Lasso
Overfitting in Polynomial Regression can be prevented by using regularization techniques like Ridge and Lasso. These techniques add a penalty term to the loss function, constraining the coefficients and reducing the complexity of the model.
What are the implications of using R-Squared vs. Adjusted R-Squared in a multiple regression model with many predictors?
- R-Squared favors complex models; Adjusted R-Squared is more sensitive to noise
- R-Squared favors more predictors without penalty; Adjusted R-Squared penalizes unnecessary predictors
- R-Squared is better for small datasets; Adjusted R-Squared is only applicable to linear models
- R-Squared provides better interpretability; Adjusted R-Squared favors simple models
In multiple regression models with many predictors, using R-Squared may favor the inclusion of more predictors without penalizing for their irrelevance, leading to potentially overfitted models. In contrast, Adjusted R-Squared includes a penalty term for unnecessary predictors, providing a more balanced assessment of the model's performance. It helps in avoiding the trap of increasing complexity without meaningful gains in explanatory power.
Which Machine Learning approach allows the system to learn and make decisions from experience?
- Reinforcement Learning
- Semi-Supervised Learning
- Supervised Learning
- Unsupervised Learning
Reinforcement Learning allows the system to learn and make decisions through trial and error, receiving rewards or penalties, and learning from experience to achieve a specific goal.