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Choose an option to check your answer.
A.
An alternative split that approximates the chosen split when its feature is missing
B.
A split generated from the target label
C.
A rule with zero information gain
D.
A branch used only for pruning
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Correct Answer: A. An alternative split that approximates the chosen split when its feature is missing
Explanation:
Surrogate splits preserve routing when the primary split value is unavailable.
They are based on other features that produce similar partitions.
Choose an option to check your answer.
A.
By converting every value to a class label manually
B.
By using support counts
C.
By ignoring the feature
D.
By testing thresholds such as x ≤ t
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Correct Answer: D. By testing thresholds such as x ≤ t
Explanation:
Candidate thresholds divide ordered numeric values into regions.
The algorithm selects a threshold that improves class purity.
Choose an option to check your answer.
A.
Replace entropy with Euclidean distance
B.
Increase tree depth automatically
C.
Adjust information gain for the intrinsic information of a split
D.
Calculate rule confidence
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Correct Answer: C. Adjust information gain for the intrinsic information of a split
Explanation:
Gain ratio penalizes splits that fragment data into many small groups.
It is used in algorithms such as C4.5.
Choose an option to check your answer.
A.
It favors only binary attributes
B.
It may favor attributes with many distinct values
C.
It ignores class distributions
D.
It always selects the least useful feature
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Correct Answer: B. It may favor attributes with many distinct values
Explanation:
A high-cardinality attribute can create many pure but tiny partitions.
Gain ratio or regularization can reduce this preference.
Choose an option to check your answer.
A.
Splits depend on order and thresholds rather than distance magnitude
B.
Trees accept only categorical variables
C.
Scaling destroys class labels
D.
All tree features must have variance one
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Correct Answer: A. Splits depend on order and thresholds rather than distance magnitude
Explanation:
Multiplying a feature by a positive constant changes threshold values but not ordering.
Distance-based domination is therefore not a concern.
Choose an option to check your answer.
A.
By requiring a linear equation only
B.
By using no features
C.
By sorting classes alphabetically
D.
By combining multiple axis-aligned splits
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Correct Answer: D. By combining multiple axis-aligned splits
Explanation:
A sequence of feature thresholds partitions the space into rectangular regions.
These regions can approximate complex nonlinear boundaries.
Choose an option to check your answer.
A.
It cannot represent nonlinear relationships
B.
It requires standardized features
C.
It can create leaves for noise and rare training cases
D.
It always predicts the majority class
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Correct Answer: C. It can create leaves for noise and rare training cases
Explanation:
Deep branches may capture accidental patterns unique to training data.
Simplification reduces this variance.
Choose an option to check your answer.
A.
Stopping at the root
B.
Growing a larger tree and then removing weak subtrees
C.
Normalizing features after training
D.
Changing class labels after prediction
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Correct Answer: B. Growing a larger tree and then removing weak subtrees
Explanation:
Post-pruning evaluates whether replacing subtrees with simpler leaves improves estimated generalization.
It often produces better control than very early stopping.
Choose an option to check your answer.
A.
Stopping tree growth before leaves become overly specific
B.
Growing a full tree and trimming it later
C.
Removing training examples
D.
Pruning input features before collecting data
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Correct Answer: A. Stopping tree growth before leaves become overly specific
Explanation:
Pre-pruning uses conditions such as maximum depth or minimum node size.
It prevents excessive complexity during induction.
Choose an option to check your answer.
A.
Adding every possible feature split
B.
Converting the tree to a graph database
C.
Deleting the target class
D.
Removing branches that add complexity without sufficient generalization benefit
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Correct Answer: D. Removing branches that add complexity without sufficient generalization benefit
Explanation:
Pruning reduces overfitting by simplifying weak or noisy branches.
It can improve test performance and interpretability.
Choose an option to check your answer.
A.
They have no parameters
B.
They always contain one node
C.
Predictions can be traced through explicit feature-based rules
D.
They use only binary data
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Correct Answer: C. Predictions can be traced through explicit feature-based rules
Explanation:
A root-to-leaf path forms an understandable if-then rule.
This transparency supports explanation and auditing.
Choose an option to check your answer.
A.
The split guaranteeing the globally smallest tree
B.
The split giving the best immediate impurity reduction
C.
A random split in every case
D.
The split using the last feature
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Correct Answer: B. The split giving the best immediate impurity reduction
Explanation:
Standard tree induction makes locally optimal choices at each node.
It does not usually search every possible complete tree.