
Certified Tester AI Testing
Domain 3Objective 8
Underfitting CT-AI Practice Questions (Page 1)
Part of the Domain 3: Machine Learning (ML) - Overview domain, which makes up ~15% of our current practice bank. ISTQB does not publish an official question count, but from its 60-minute exam (~25–40 total, ~4–6 in this domain), expect 1–1 from this objective — we provide 22 practice questions to prepare you well beyond it. (estimate)
22questions here
5free pages
5concepts
Questions 1–5
- 1
A team is using a deep neural network to classify images. The model achieves 85% accuracy on the training set and 84% on the validation set, but the target is 95%. The team suspects the model is underfitting. Which change is most likely to help?
Select an answer first - 2
A data scientist is training a model to predict equipment failure. The model achieves 99% accuracy on the training set but only 55% accuracy on the test set. The classes are highly imbalanced (95% no-failure, 5% failure). The data scientist initially suspects overfitting. However, after reviewing the learning curves, they see that both training and validation accuracy are high and flat. What is the most likely issue?
Select an answer first - 3
Which action is most likely to help reduce underfitting?
Select an answer first - 4
A data scientist is training a model and observes that the training loss is decreasing, but the validation loss is increasing. They suspect overfitting and apply early stopping. After early stopping, both training and validation loss are high. What is the most likely issue?
Select an answer first - 5
A team is using a neural network for image classification. The model is underfitting, with 70% accuracy on both training and validation sets. The team decides to increase the model's capacity by adding more layers. After the change, the training accuracy rises to 98%, but the validation accuracy drops to 65%. What should the team do next?
Select an answer first
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