Machine Learning Key Concepts: A Quick Review

Machine Learning Key Concepts

1. You have a dataset with 7 features and 3 different labels. Which of the following would be a valid NN model? All of the above

2. Which of the following is not a data preprocessing task? Data translation

3. On a neural network, the output layer represents… Labels

6. Which is the output of this code? [[0,0,1], [0, 1,0],[1,0,0]]

7. What does this confusion matrix represent, where 1= positive and 0 = negative & T=True and F=False? TP=41, TN=116, FP=9, FN=26

9. With data binning you can achieve … All of the above

10. What should we do to deal with the Bias-Variance Trade-off dilemma? Find the point that minimizes the MSE

11. The PCA method allows you to reduce the number of features of a huge dataset Yes, by obtaining the eigenvalues of the covariance matrix

12. An automatic vacuum cleaner begins navigating through your flat to make a map as a base for cleaning your home. This behavior is: Model free

13. On a CNN with stride=3, which will be the upper-left value of the next “square” to analyze? 2

14. On CNN algorithms, what is padding? To add zeroes out of the borders of the dataset to avoid underrepresent them

15. On a neural network, what is the purpose of the activation function… a and b are true

16. On a CNN, what is a kernel? A sort of window to perform operations on the whole dataset by moving it

17. In bagging we … Divide the dataset in bags and train and test with each

18. Which are the axis on a plot for the Elbow method? All of the above

20. In k-Fold cross validation we … Split the dataset in groups and use each group to test the remaining data (used as train data)

21. On a neural network, why do you choose initially the weights of neurons randomly? You don’t have any information of the neurons at the beginning

23. On hierarchical clustering we begin by assigning each observation to its own 1-point cluster. Yes

24. Which clustering method would you use to clusterize these observations? DBScan

25. What do you plot on a silhouette graphic? Silhouette coefficient of each point, grouped by its cluster

26. On NN algorithms, what is a batch? One or more samples considered by the model within an epoch before weights are updated

27. With a ReLu activation function … The neuron activates above zero and output is linear

28. What would you conclude from this silhouette plot? We should try with less clusters to get better silhouette

30. On a Reinforcement ML system, what’s the value? The expected long-term return with discount

31. A robotic arm must open the leg of a patient and once the bone is reached, let the doctor finish the operation. Which is the environment on this ML system? The patient

32. On the Bias-Variance Trade-off dilemma, underfitting implies: High bias and low variance

33. A neural network, … Divides the feature space allowing classifying observations

34. GPT means Generative Pretrained Transformers. Why do you think they are pretrained? Like any ML algorithm you train it and then release to real data

35. On a neural network, hidden layers represent… None of the above

36. A robotic arm has to open the leg of a patient and once the bone is reached, let the doctor finish the operation. Which are the actions on this ML system? Movements and actions of the robot

37. Linear regression is a ML algorithm Yes, because it predicts outcomes based on training data

38. On the Bias-Variance Trade-off dilemma, overfitting implies: Low bias and high variance