Practice
1.
import torch
x = torch.tensor([-1.0, 0.0, 1.0])
output = torch.nn.functional.relu(x)
print(output)What is the output of this code?easy
Solution
Step 1: Understand ReLU behavior.
ReLU outputs zero for negative inputs and the input itself for non-negative inputs.Step 2: Apply ReLU to each element.
For -1.0, output is 0.0; for 0.0, output is 0.0; for 1.0, output is 1.0.Final Answer:
Option A -> Option AQuick Check:
ReLU zeros negatives, keeps positives. [OK]
Hint: ReLU zeros negatives, keeps positives. [OK]
Common Mistakes:
2. In the context of feature selection, which method evaluates features based on their statistical relationship with the target variable without involving a predictive model?
easy
Solution
Step 1: Identify the method type.
Filter methods evaluate features based on statistical measures like correlation, without using a predictive model.Step 2: Eliminate wrong options.
Wrapper methods use a predictive model to evaluate feature subsets. Embedded methods select features during model training. Recursive feature elimination is a type of wrapper method.Final Answer:
Option C -> Option CQuick Check:
Filter = Stats, no model. [OK]
Hint: Filter methods use statistics, not models. [OK]
Common Mistakes:
3. In the context of handling class imbalance, which technique is specifically designed to adjust the loss function to focus more on hard-to-classify examples?
easy
Solution
Step 1: Identify the technique that modifies the loss function.
Focal Loss is designed to focus more on hard-to-classify examples by adjusting the loss function.Step 2: Eliminate wrong options.
Oversampling and undersampling adjust the dataset, not the loss function. Cost-sensitive learning modifies the cost, not the focus on hard examples.Final Answer:
Option D -> Option DQuick Check:
Focal Loss focuses on hard examples. [OK]
Hint: Focal Loss focuses on hard examples. [OK]
Common Mistakes:
4. In a scenario where computational resources are limited, which approach is more suitable for hyperparameter tuning and why?
medium
Solution
Step 1: Evaluate resource constraints
Cross-validation is computationally expensive but provides robust tuning.Step 2: Eliminate less suitable options
Use a single train-test split to save resources. risks overfitting. Use a train-validation split and skip the test set. skips the test set, risking unseen data performance. Use a larger test set to ensure model generalization. misallocates resources to testing rather than tuning.Final Answer:
Option C -> Option CQuick Check:
Cross-validation ensures robust tuning despite cost. [OK]
Hint: Cross-validation ensures robust tuning despite cost. [OK]
Common Mistakes:
5. A model performs well on the validation set but poorly on the test set. What is the most likely cause?
medium
Solution
Step 1: Identify the discrepancy
Good validation performance but poor test performance suggests a mismatch between sets.Step 2: Eliminate less likely causes
The model is underfitting the data. is incorrect as underfitting would affect both sets. The validation set is too small. is less likely unless the validation set is extremely small. The model has too many parameters. would likely affect both sets similarly.Final Answer:
Option A -> Option AQuick Check:
Mismatch between validation and test sets. [OK]
Hint: Mismatch between validation and test sets. [OK]
Common Mistakes:
