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FRM Part I · FRM Exam Part I · Machine Learning and Prediction

A fraud model is evaluated on 10,000 transactions, of which 100 are fraudulent. A naive model that labels every transaction as non-fraud is compared to a real model with 90% accuracy that catches 80 of the frauds. Which statement is most accurate?

The naive model achieves 99% accuracy yet zero recall, since it never identifies a fraud. With highly imbalanced classes, accuracy is a poor measure, and metrics such as recall, precision or F1 better reflect usefulness.

  1. AThe naive model has 99% accuracy but zero recall, so accuracy is a poor metric hereCorrect
  2. BThe naive model has 99% accuracy and perfect recall
  3. CThe real model is worse because its accuracy is lower, so it should be chosen less
  4. DThe naive model has 1% accuracy because it detects no fraud

Explanation

The naive model is correct on 9,900 of 10,000 transactions, giving 99% accuracy, but it catches none of the 100 frauds, so recall is 0. With imbalanced classes accuracy misleads; recall, precision or F1 are better. The other options misstate these values.

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