About this Study Set
This study set covers Data Science through
20 practice questions.
A rigorous set of questions covering statistical analysis, machine learning foundations, and data ethics. Every question includes the correct answer so you can learn as you go — pick any format above to get started.
Questions & Answers
Browse all 20 questions from the
Advanced Data Science Concepts study set below.
Each question shows the correct answer — select a study format above to practice interactively.
1
Which statistical measure is most resilient to the influence of outliers in a skewed dataset?
-
A
Arithmetic Mean
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B
Median
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C
Mode
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D
Range
2
In the context of supervised learning, what does the 'Bias-Variance Tradeoff' describe?
-
A
The relationship between model complexity and error
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B
The speed of CPU vs GPU processing
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C
The difference between training data and validation data
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D
The cost of data storage vs retrieval speed
3
What is the primary objective of applying 'Normalization' to numerical input features in a machine learning model?
-
A
To remove missing values
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B
To increase the number of dimensions
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C
To scale values to a standard range, usually 0 to 1
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D
To convert categorical labels into integers
4
Which term describes the phenomenon where a model performs exceptionally well on training data but fails to generalize to new, unseen data?
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A
Underfitting
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B
Gradient Descent
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C
Overfitting
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D
Feature Selection
5
What is the 'Curse of Dimensionality' in data science?
-
A
The difficulty of visualizing data in 3D
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B
The exponential increase in data volume as dimensions grow
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C
The requirement for more data as the number of features increases to maintain statistical significance
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D
The inability of computers to process high-resolution images
6
In a confusion matrix for a binary classifier, what does the 'False Negative' rate represent?
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A
Type I error
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B
Type II error
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C
Accuracy
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D
Precision
7
Which algorithm is fundamentally based on the concept of maximizing the margin between classes in a vector space?
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A
K-Means Clustering
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B
Support Vector Machine
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C
Linear Regression
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D
Decision Tree
8
What does the 'p-value' indicate in the context of hypothesis testing?
-
A
The probability that the null hypothesis is true
-
B
The effect size of the experiment
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C
The significance level of the independent variable
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D
The correlation coefficient of the data
9
Which data preprocessing technique is used to handle categorical variables by creating binary columns for each category?
-
A
Standardization
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B
One-Hot Encoding
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C
Logarithmic Transformation
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D
Feature Aggregation
10
In SQL, which clause is used to filter aggregated data after a GROUP BY operation has been performed?
-
A
WHERE
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B
HAVING
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C
ORDER BY
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D
LIMIT
11
What is the primary purpose of cross-validation in model evaluation?
-
A
To speed up training time
-
B
To reduce the amount of training data needed
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C
To provide a more robust estimate of model performance on unseen data
-
D
To optimize the hyperparameters automatically
12
Which of the following is a non-parametric machine learning algorithm that classifies data points based on their proximity to neighbors?
-
A
Logistic Regression
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B
K-Nearest Neighbors
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C
Naive Bayes
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D
Random Forest
13
In the context of information theory, what metric is commonly used to measure the impurity of a node in a decision tree?
-
A
Gini Impurity
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B
Euclidean Distance
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C
Standard Deviation
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D
Manhattan Distance
14
Which mathematical operation is at the core of the backpropagation algorithm in neural networks?
-
A
Integration
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B
Chain Rule of Calculus
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C
Long Division
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D
Matrix Transposition
15
What does the 'F1-Score' represent in classification evaluation?
-
A
The sum of precision and recall
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B
The difference between true positives and false positives
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C
The harmonic mean of precision and recall
-
D
The ratio of accuracy to error rate
16
Which type of regularization adds a penalty equal to the absolute value of the magnitude of coefficients, often leading to sparse models?
-
A
L1 Regularization (Lasso)
-
B
L2 Regularization (Ridge)
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C
Elastic Net
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D
Dropout
17
What is the main advantage of using a 'Random Forest' over a single 'Decision Tree'?
-
A
Reduced computational cost
-
B
Improved interpretability
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C
Reduction of variance via bagging
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D
Increased bias
18
Which statistical term refers to the correlation between two variables where the influence of a third variable is controlled?
-
A
Partial Correlation
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B
Spurious Correlation
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C
Covariance
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D
Multicollinearity
19
In time-series analysis, what does 'Stationarity' imply about a dataset?
-
A
The mean and variance remain constant over time
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B
The data exhibits a strong seasonal trend
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C
The data has no missing values
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D
The data is linearly distributed
20
Which encoding technique is best suited for ordinal categorical data where the order of categories matters?
-
A
Label Encoding
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B
One-Hot Encoding
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C
Dummy Encoding
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D
Frequency Encoding
