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.
- AThe naive model has 99% accuracy but zero recall, so accuracy is a poor metric hereCorrect
- BThe naive model has 99% accuracy and perfect recall
- CThe real model is worse because its accuracy is lower, so it should be chosen less
- 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.
Did you get it right without looking?
One question tells you little. A timed set on Machine Learning and Prediction shows your real accuracy, how long you take and where you lose marks.
More Machine Learning and Prediction questions
- Which feature of a random forest distinguishes it from plain bagging of decision trees?
- In the bias-variance tradeoff, increasing the complexity of a model (for example, adding many polynomial terms) typically has which effect?
- In a K-means run with K = 2, five one-dimensional observations are 1, 2, 4, 9 and 10. The initial centroids are 2 and 9. After assigning eac…
- A fraud model is evaluated on 1,000 transactions. The confusion matrix shows: true positives 30, false positives 20, false negatives 10, tru…
- An analyst uses ridge regression with one predictor and no intercept, where the predictor has been scaled so that the sum of x squared equal…
- A bank uses the first three principal components of 12 equity factor returns as regressors in a model to predict portfolio losses (principal…