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Graded Quiz: Convolutional Neural Network Development :AI Capstone Project with Deep Learning (IBM AI Engineering Professional Certificate) Answers 2025

1. Which metric should Jane use to measure how well the model distinguishes between classes?

❌ Mean Squared Error
AU-ROC (Area Under ROC Curve)
❌ Model accuracy
❌ Cross-entropy loss

Explanation:
AU-ROC evaluates how well the model separates classes across all thresholds, making it ideal for classification performance assessment.


2. What key component must Liam include in a CNN model for image classification?

❌ Dropout layers to increase model capacity
❌ Recurrent layers to capture temporal sequences
Convolutional layers to extract spatial features
❌ Batch normalization layers to reduce model size

Explanation:
Convolutional layers are the core of CNNs, extracting spatial patterns such as edges, textures, and shapes in images.


3. What should the AgriTech team do first when building a CNN classifier in Keras?

❌ Compile the CNN model
Preprocess the dataset to ensure all images are the same size
❌ Initialize the CNN model architecture
❌ Train the CNN model

Explanation:
All images must be resized and normalized before feeding them into the model; preprocessing is always the first step.


4. Why is HeUniform() used as a kernel initializer?

❌ It regularizes the model with L2 norms
It initializes weights suited to ReLU-based activations
❌ It schedules the learning rate automatically
❌ It freezes pretrained ImageNet weights

Explanation:
He initialization prevents vanishing/exploding gradients and works best with ReLU or variants.


5. Why is torch.no_grad() used during validation?

To disable gradient calculation, saving memory and computation
❌ To randomize batch order
❌ To reset model weights
❌ To enable GPU acceleration

Explanation:
torch.no_grad() ensures no gradients are tracked, making evaluation faster and more memory-efficient.


6. Why is F1 Score preferred for highly imbalanced datasets?

❌ It considers only true positives and true negatives
❌ It measures area under the precision-recall curve
It balances precision and recall, focusing on minority-class performance
❌ It is threshold-independent like ROC-AUC

Explanation:
F1 is the harmonic mean of precision and recall, giving a fairer performance measure when classes are imbalanced.


7. How can you generate a detailed summary with per-class precision, recall, and F1?

❌ accuracy_score
classification_report
❌ roc_curve
❌ confusion_matrix

Explanation:
classification_report outputs precision, recall, F1-score, and support for each class.


🧾 Summary Table

Q# Correct Answer Key Concept
1 AU-ROC Class-separation ability
2 Convolutional layers Spatial feature extraction
3 Preprocess the dataset CNN pipeline order
4 HeUniform Weight initialization for ReLU
5 torch.no_grad() No gradients during evaluation
6 F1 Score Handling imbalance
7 classification_report Per-class metrics