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Machine Learning

Performance Metrics

Interview questions on Performance Metrics.

48 questions

Classification Metrics

Q1. What metrics we can use to evaluate a classifier?

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Classification Metrics

Q2. What is the purpose of a confusion matrix?

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Classification Metrics

Q3. Explain True Positive (TP) and False Positive (FP).

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Classification Metrics

Q4. Define True Negative (TN) and False Negative (FN).

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Classification Metrics

Q5. How can you use a confusion matrix to choose an appropriate threshold for a binary classifier?

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Classification Metrics

Q7. Write the mathematical expression of accuracy score?

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Classification Metrics

Q9. How does accuracy is related with negative log(logistic) loss?

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Classification Metrics

Q10. What is the main issue with accuracy score?

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Classification Metrics

Q11. How can we overcome with accuracy score limitations?

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Classification Metrics

Q12. What do you mean by precision? How can we calculate it?

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Classification Metrics

Q14. What is the range of precision value?

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Classification Metrics

Q15. What are the weaknesses of precision as a metric in classification, and how can it be misleading in certain scenarios?

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Classification Metrics

Q16. State one scenario where you should use precision of the system as evaluation metric?

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Classification Metrics

Q19. What does recall measures? How is it calculated?

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Classification Metrics

Q20. What does higher value of recall indicates?

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Classification Metrics

Q23. What is the main limitation of recall metric?

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Classification Metrics

Q24. State one scenario where recall is more desirable?

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Classification Metrics

Q25. Explain the tradeoff between recall and precision?

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Classification Metrics

Q27. What is F-1 Score? When should we use it?

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Classification Metrics

Q29. What are the weaknesses of F-1 score?

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Classification Metrics

Q30. Explain the difference between Type I and Type II errors in the context of a confusion matrix.

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Classification Metrics

Q31. What is the main limitations with confusion matrix summarization?

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Classification Metrics

Q33. State the use of precision and recall curve?

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Classification Metrics

Q34. How can we construct precision and recall curve?

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Classification Metrics

Q35. What are the limitations of precision and recall curve?

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Classification Metrics

Q37. For an ideal model what should ROC-AUC?

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Classification Metrics

Q38. State what does mean to have AUC of 0.2?

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Classification Metrics

Q39. Can we use ROC-AUC score for multi-class classification?

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Classification Metrics

Q41. What is the limitations of ROC-AUC score?

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Classification Metrics

Q42. Your team is building a system to aid doctors in predicting whether a patient has cancer or not from their X-ray scan. Your colleague announces that the problem is solved now that they’ve built a system that can predict with 99.99% accuracy. How would you respond to that claim?

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Classification Metrics

Q43. Given a binary classifier that outputs the following confusion matrix.

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[""Predicted TruePredicted FalseActual True3020Actual False540]\begin{bmatrix} \textbf{""} & \textbf{Predicted True} & \textbf{Predicted False} \\\\ \textbf{Actual True} & 30 & 20 \\\\ \textbf{Actual False} & 5 & 40 \\\\ \end{bmatrix}

  1. Calculate the model’s precision, recall, and F1.
  2. What can we do to improve the model’s performance?

Classification Metrics

Q44. Consider a classification where $99%$ of data belongs to class A and $1%$ of data belongs to class B.

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  1. If your model predicts A 100% of the time, what would the F1 score be? Hint: The F1 score when A is mapped to 0 and B to 1 is different from the F1 score when A is mapped to 1 and B to 0.
  2. If we have a model that predicts A and B at a random (uniformly), what would the expected F1F_1 be?

Classification Metrics

Q45. Show that the negative log-likelihood and cross-entropy are the same for binary classification tasks.

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Classification Metrics

Q46. For classification tasks with more than two labels (e.g. MNIST with $10$ labels), why is cross-entropy a better loss function than MSE?

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Classification Metrics

Q47. Consider a language with an alphabet of $27$ characters. What would be the maximal entropy of this language?

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Classification Metrics

Q48. Suppose you want to build a model to predict the price of a stock in the next 8 hours and that the predicted price should never be off more than $10%$ from the actual price. Which metric would you use?

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