MCQ Collection
Data Mining MCQs
Practice Data Mining questions with answers and explanations.
Choose an option to check your answer.
A.
The median
B.
The interquartile range
C.
The arithmetic mean
D.
The mode
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Correct Answer: C. The arithmetic mean
Explanation:
The mean uses the magnitude of every observation.
Choose an option to check your answer.
A.
The support of X minus Y
B.
The confidence of Y → X
C.
The support of X ∪ Y
D.
The number of items in X
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Correct Answer: C. The support of X ∪ Y
Explanation:
A rule is supported by transactions containing both antecedent and consequent.
Choose an option to check your answer.
A.
It guarantees no itemsets are found
B.
It makes confidence undefined for every rule
C.
It can produce an enormous number of patterns, many of limited value
D.
It removes rare patterns
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Correct Answer: C. It can produce an enormous number of patterns, many of limited value
Explanation:
Lower support allows many combinations to qualify as frequent.
Choose an option to check your answer.
A.
It cannot compute support
B.
It works only with continuous data
C.
It may generate a huge number of candidate itemsets
D.
It requires labeled classes
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Correct Answer: C. It may generate a huge number of candidate itemsets
Explanation:
Dense datasets and low support thresholds cause candidate explosion.
Choose an option to check your answer.
A.
The median always preserves correlations
B.
The median creates new observations
C.
The median guarantees normality
D.
The median is less affected by extreme values
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Correct Answer: D. The median is less affected by extreme values
Explanation:
For skewed numeric variables, the median often better represents the center.
Choose an option to check your answer.
A.
The full range
B.
The variance
C.
The standard deviation
D.
The interquartile range
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Correct Answer: D. The interquartile range
Explanation:
The IQR depends on the first and third quartiles.
Choose an option to check your answer.
A.
support(X) divided by support(Y)
B.
support(Y) minus support(X)
C.
support(X ∩ Y) divided by all items
D.
support(X ∪ Y) divided by support(X)
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Correct Answer: D. support(X ∪ Y) divided by support(X)
Explanation:
Confidence estimates the conditional probability of Y given X.
Choose an option to check your answer.
A.
It always increases false positives
B.
It makes every itemset frequent
C.
It prevents transaction scanning
D.
It can miss rare but important associations
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Correct Answer: D. It can miss rare but important associations
Explanation:
Some valuable patterns, such as rare adverse events, naturally have low support.
Choose an option to check your answer.
A.
When the item universe is tiny and support is high
B.
When there is one transaction only
C.
When all items are absent
D.
When transactions are dense and many long patterns are frequent
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Correct Answer: D. When transactions are dense and many long patterns are frequent
Explanation:
Dense data produce many possible combinations and long candidates.
Choose an option to check your answer.
A.
Use the most frequent category or a separate 'Unknown' category
B.
Use the arithmetic mean
C.
Use the standard deviation
D.
Apply logarithmic transformation
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Correct Answer: A. Use the most frequent category or a separate 'Unknown' category
Explanation:
Categorical values require a valid category rather than a numeric summary.
Choose an option to check your answer.
A.
As the average squared deviation from the mean
B.
As the difference between maximum and minimum
C.
As the median of all values
D.
As the most frequent value
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Correct Answer: A. As the average squared deviation from the mean
Explanation:
Squaring prevents deviations of opposite signs from cancelling.
Choose an option to check your answer.
A.
Transactions containing X often also contain Y
B.
X occurs in most transactions necessarily
C.
Y causes X
D.
X and Y are negatively correlated
Show Answer
Correct Answer: A. Transactions containing X often also contain Y
Explanation:
Confidence focuses on the conditional frequency of Y among X transactions.
