MCQ Collection
Data Mining MCQs
Practice Data Mining questions with answers and explanations.
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Correct Answer: B. Using one-vs-rest or one-vs-one strategies
Explanation:
Multiple binary classifiers are trained and their outputs combined.
Libraries typically implement one of these strategies automatically.
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Correct Answer: D. Cohesion within its cluster against separation from the nearest other cluster
Explanation:
Values near one indicate a well-matched cluster assignment.
Values near or below zero suggest overlap or possible misassignment.
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Correct Answer: B. Their weight vectors are adjusted toward the input
Explanation:
Neighborhood updates encourage nearby grid units to represent similar regions.
This creates topological organization.
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Correct Answer: B. A boundary enclosing the region occupied by normal data
Explanation:
The method distinguishes the normal data region from the origin or outside space.
New points beyond the learned boundary are flagged.
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Correct Answer: C. To accelerate retrieval of nearby points
Explanation:
Structures such as k-d trees partition feature space for faster queries.
Their effectiveness can decline in very high dimensions.
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Correct Answer: C. One classifier per class against all remaining classes
Explanation:
Each classifier separates one target class from the rest.
The class with the strongest decision score is often selected.
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Correct Answer: A. It represents clusters by coordinate-wise medians and commonly uses absolute distance
Explanation:
K-medians minimizes an L1-style objective rather than squared error.
Medians are less sensitive to extreme values than means.
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Correct Answer: C. Training shifts from global ordering to fine local adjustment
Explanation:
Large early neighborhoods organize the whole map coherently.
Smaller later neighborhoods refine local prototypes.
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Correct Answer: C. Too many false alarms can overwhelm investigators
Explanation:
Precision indicates how many alerts are truly anomalous.
Low precision creates operational cost and alert fatigue.
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Correct Answer: D. Numeric code differences may imply nonexistent order and distances
Explanation:
Encoding red, blue, and green as 1, 2, and 3 creates artificial spacing.
Appropriate one-hot encoding or mixed-type distances should be used.
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Correct Answer: D. The native SVM output is a margin score rather than a posterior probability
Explanation:
Methods such as Platt scaling map decision scores to probabilities.
Calibration should use separate or cross-validated data.
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Correct Answer: B. When numeric data contain substantial outliers
Explanation:
Absolute deviations and median centers reduce the influence of extremes.
This can produce more robust cluster locations.