juniorModel Evaluation
What is accuracy in model evaluation?
Updated May 17, 2026
Short answer
Accuracy measures the proportion of correct predictions over total predictions.
Deep explanation
Accuracy = (TP + TN) / (TP + TN + FP + FN). It works well for balanced datasets but can be misleading for imbalanced ones.
Real-world example
Spam detection systems often report accuracy but rely on precision/recall for deeper evaluation.
Common mistakes
- Using accuracy for heavily imbalanced datasets.
Follow-up questions
- When is accuracy misleading?
- What metric should replace it?