Machine Learning quiz 2

Which of the following is used for unsupervised learning task?

• Gaussian Mixture model

• K-Means

• ID3

• Multiplayer Perception

Which of the following is a widely used and effective machine learning algorithm based on the idea of bagging?

• Decision tree

• Regression

• Classification

• Random forest

To find the minimum or maximum of a function, we set the gradient to zero because;

• The value of a function at extrema is always zero

• Depends on the type of problem

• Both A and B

• None of the above

The most widely used tools and metrics to assess a classification model are:

• Confusion matrix

• Cost-sensitive accuracy

• Area under the ROC curve

• All of the above

Which of the following is a good test dataset charateristic?

• Large enough to yield meaningful results

• Is a representative of the dataset as a whole

• Both A and B

• None of the above

Which of the following is a disadvantage of decision trees?

• Factor analysis

• Decision trees are robust to outliers

• Decision trees are prone to overfit

• None of the above

How do you handle missing or corrupted data in a dataset?

• Drop missing rows or collumns

• Replace missing values with Mean/Median/Mode

• Assign a unique category to the missing values

• All of the above

What is the purpose of performing cross-validation?

• To access the predictive performance of the models

• To judge how the trained model performs outside the sample on test data.

• Both A and B

Why is second order differencing in time series needed?

• To remove stationarity

• To find the maxima or minima at the local point

• Both A and B

• None of the above

When performing regression or classification, which of the following is the correct way to preprocess data?

• Normalize the data -> PCA -> Training

• PCA -> Normalize PCA output -> Training

• Normalize the data -> PCA -> Normalize PCA output -> Training

• None of the above