MCQs cover the fundamentals of Exploratory Data Analysis, covering data summarization, visualization techniques, handling anomalies, and inferring patterns from datasets. Ideal for data analysts and scientists to reinforce EDA practices using statistical and graphical methods.
1. What is the primary goal of Exploratory Data Analysis (EDA)?
Correct Answer: b) To understand the data and uncover patterns
Explanation:
EDA aims to summarize main characteristics, often using visual methods, to reveal insights and detect anomalies before modeling.
2. Which statistic measures the central tendency of a dataset?
Correct Answer: b) Mean
Explanation:
The mean is the average value, representing the center of the data distribution.
3. A histogram is primarily used for visualizing
Correct Answer: b) Distribution of a single numerical variable
Explanation:
Histograms divide continuous data into bins to show frequency distribution.
4. What does the interquartile range (IQR) represent?
Correct Answer: b) The middle 50% of the data
Explanation:
IQR = Q3 - Q1, measuring spread of the central half of the data.
5. In EDA, missing values are often identified using
Correct Answer: b) Summary functions like isnull()
Explanation:
Functions like df.isnull().sum() count missing entries per column.
6. Which plot is best for detecting outliers in numerical data?
Correct Answer: b) Box plot
Explanation:
Box plots display quartiles and whiskers, highlighting points beyond 1.5 * IQR.
7. The correlation coefficient ranges from
Correct Answer: b) -1 to 1
Explanation:
Pearson's r measures linear relationship strength and direction between -1 and 1.
8. Skewness measures the
Correct Answer: b) Asymmetry of the distribution
Explanation:
Positive skew indicates right tail, negative left; zero for symmetric.
9. A scatter plot visualizes
Correct Answer: b) Relationship between two variables
Explanation:
Scatter plots plot points for two continuous variables to show correlation or trends.
10. What is the purpose of a pair plot in EDA?
Correct Answer: b) To visualize pairwise relationships in multivariate data
Explanation:
Pair plots create a matrix of scatter plots and histograms for all variable pairs.
11. Kurtosis describes the
Correct Answer: a) Tail heaviness relative to normal distribution
Explanation:
High kurtosis indicates heavy tails and peaked center; low indicates flat.
12. For categorical data, which visualization is appropriate?
Correct Answer: b) Bar chart
Explanation:
Bar charts display frequencies or counts for discrete categories.
13. The standard deviation measures
Correct Answer: b) Dispersion around the mean
Explanation:
SD quantifies data variability; sqrt of variance.
14. In EDA, data scaling is often checked for
Correct Answer: b) Feature ranges and distributions
Explanation:
Scaling ensures features contribute equally, checked via min-max or z-scores.
15. A heatmap is used to visualize
Correct Answer: b) Correlation matrices
Explanation:
Heatmaps color-code values in a matrix, ideal for correlations.
16. What indicates a normal distribution in EDA?
Correct Answer: a) Skewness = 0, Kurtosis = 3
Explanation:
Normal distribution is symmetric (skew=0) with kurtosis=3 (mesokurtic).
17. Violin plots combine
Correct Answer: b) Box plot and density plot
Explanation:
Violin plots show distribution shape via kernel density and quartiles via box.
18. Multicollinearity is detected using
Correct Answer: a) VIF (Variance Inflation Factor)
Explanation:
VIF > 5-10 indicates high multicollinearity among features.
19. For time series EDA, which plot shows trends over time?
Correct Answer: b) Line plot
Explanation:
Line plots connect data points chronologically to reveal patterns.
20. The mode is the value that
Correct Answer: b) Occurs most frequently
Explanation:
Mode identifies the most common category or value in unimodal data.
21. In EDA, pivot tables are used for
Correct Answer: a) Aggregating data by categories
Explanation:
Pivot tables summarize data with rows, columns, and values for cross-tabulation.
22. A Q-Q plot assesses
Correct Answer: a) Normality of distribution
Explanation:
Q-Q plots compare quantiles to theoretical normal; straight line indicates normality.
23. Handling outliers in EDA often involves
Correct Answer: b) Capping or removing after investigation
Explanation:
Outliers may be errors or insights; decisions based on domain knowledge.
24. Categorical variables are encoded in EDA using
Correct Answer: a) One-hot encoding
Explanation:
One-hot creates binary columns for categories to avoid ordinal assumptions.
25. The coefficient of variation (CV) is
Correct Answer: a) SD / Mean * 100%
Explanation:
CV measures relative variability, useful for comparing dispersion across datasets.
26. Seaborn library in Python is popular for EDA because it
Correct Answer: b) Provides statistical visualizations
Explanation:
Seaborn builds on Matplotlib for attractive, informative plots like heatmaps.
27. In bivariate analysis, a low correlation implies
Correct Answer: b) Weak or no linear relationship
Explanation:
Correlation near 0 suggests little linear association between variables.
28. Data profiling in EDA includes
Correct Answer: b) Summary statistics and data quality checks
Explanation:
Profiling overviews structure, types, missingness, and stats.
29. A kernel density estimate (KDE) plot shows
Correct Answer: b) Smooth probability density
Explanation:
KDE approximates continuous distribution using a kernel function.
30. For imbalanced classes in EDA, check
Correct Answer: a) Class distribution via bar plots
Explanation:
Visualize target variable frequencies to identify imbalance.
31. The five-number summary includes
Correct Answer: a) Min, Q1, Median, Q3, Max
Explanation:
Used in box plots to describe data spread without assuming distribution.
32. In EDA, feature engineering starts with
Correct Answer: a) Creating new variables from existing
Explanation:
Derive interactions, polynomials, or bins to capture patterns.
33. A lag plot in time series EDA detects
Correct Answer: b) Autocorrelation
Explanation:
Plots value against its lagged version to show serial dependence.
34. Z-score for outlier detection is
Correct Answer: a) (x - mean) / SD
Explanation:
|Z| > 3 often flags outliers assuming normality.
35. Count plots are used for
Correct Answer: b) Categorical frequencies
Explanation:
Similar to bar charts but for single categorical variable counts.
36. In EDA, dimensionality reduction preview uses
Correct Answer: a) PCA scree plot
Explanation:
Shows explained variance by components to decide retention.
37. Median is robust to
Correct Answer: a) Outliers
Explanation:
Unlike mean, median resists extreme values.
38. Joint plots in Seaborn combine
Correct Answer: b) Scatter, marginal histograms, and correlation
Explanation:
For bivariate EDA with univariate margins.
39. Variance is the average of
Correct Answer: a) Squared deviations from mean
Explanation:
Variance = Σ(x_i - μ)^2 / n, measuring spread.
40. For text data in EDA, start with
Correct Answer: a) Word clouds or n-gram frequencies
Explanation:
Visualize common terms and phrases in unstructured text.
41. Autocorrelation function (ACF) plot identifies
Correct Answer: b) Serial correlations in time series
Explanation:
ACF shows correlation of series with its lags.
42. In EDA, data types include
Correct Answer: b) Numerical, categorical, ordinal, datetime
Explanation:
Understanding types guides appropriate analysis and visualization.
43. A facet grid in EDA allows
Correct Answer: a) Subplotting by categories
Explanation:
Splits plots into a grid conditioned on variables for comparisons.
44. Pearson correlation assumes
Correct Answer: a) Linear relationship and normality
Explanation:
For continuous variables; use Spearman for non-parametric.
45. Box plot whiskers typically extend to
Correct Answer: a) 1.5 * IQR from quartiles
Explanation:
Beyond whiskers are potential outliers.
46. In EDA, resampling checks
Correct Answer: a) Stability of statistics
Explanation:
Bootstrap or jackknife assesses variability in estimates.
47. Cramér's V measures
Correct Answer: a) Association between categorical variables
Explanation:
Ranges 0-1; chi-square based for nominal data.
48. Log transformation in EDA is used to
Correct Answer: a) Handle skewed data
Explanation:
Reduces right skew, stabilizing variance.
49. A swarm plot displays
Correct Answer: a) Points without overlap for categorical
Explanation:
Shows individual data points spread to avoid stacking.
50. In multivariate EDA, parallel coordinates plot
Correct Answer: a) High-dimensional data as lines
Explanation:
Each line represents an observation across normalized axes.
51. The range is
Correct Answer: a) Max - Min
Explanation:
Simplest spread measure, sensitive to outliers.
52. For geospatial data in EDA, use
Correct Answer: a) Choropleth maps
Explanation:
Color regions by data values for spatial patterns.
53. Chi-square test in EDA checks
Correct Answer: a) Independence between categorical variables
Explanation:
Null hypothesis: no association in contingency tables.
54. Strip plots show
Correct Answer: a) Jittered points for categorical
Explanation:
Adds random noise to positions to reveal overplotting.
55. In EDA, cross-validation previews
Correct Answer: d) All of the above
Explanation:
Early CV checks generalization before full modeling.
56. Quantile-quantile (Q-Q) plot compares
Correct Answer: a) Sample to theoretical distribution
Explanation:
Deviations from line indicate non-conformity.
57. For ordinal data, use
Correct Answer: a) Ordinal encoding
Explanation:
Assigns integers preserving order, unlike nominal.
58. Partial dependence plots explain
Correct Answer: a) Feature effects in models
Explanation:
Shows marginal effect of a feature on prediction.
59. In EDA, binning continuous data creates
Correct Answer: a) Categorical intervals
Explanation:
Reduces noise and reveals patterns in discretized form.
60. Spearman's rank correlation is
Correct Answer: a) Non-parametric for monotonic relations
Explanation:
Based on ranks, robust to non-normality.
61. A ridgeline plot visualizes
Correct Answer: a) Overlapping density distributions
Explanation:
Stacks shifted KDEs for category comparisons.
62. EDA documents findings via
Correct Answer: a) Notebooks like Jupyter
Explanation:
Combines code, visuals, and narrative for reproducibility.
63. Theil's U measures
Correct Answer: a) Asymmetric association for categorical
Explanation:
Uncertainty coefficient based on entropy.
64. In time series, decomposition separates
Correct Answer: a) Trend, seasonality, residual
Explanation:
Additive or multiplicative models isolate components.
65. For high-cardinality categoricals in EDA, use
Correct Answer: a) Frequency or target encoding
Explanation:
Reduces dimensions while retaining information.
66. A contour plot shows
Correct Answer: a) Density levels in 2D
Explanation:
Lines or colors indicate constant value regions.
67. EDA hypothesis generation leads to
Correct Answer: a) Confirmatory analysis
Explanation:
Patterns suggest testable hypotheses for further stats.
68. Mahalanobis distance detects
Correct Answer: a) Multivariate outliers
Explanation:
Accounts for covariance, unlike Euclidean.
69. In EDA, groupby operations compute
Correct Answer: a) Aggregates by categories
Explanation:
Like mean by group in pandas for subgroup analysis.
70. A hexbin plot is a
Correct Answer: a) 2D histogram with hexagons
Explanation:
Efficient for dense scatter data to show counts.
71. EDA for regression checks
Correct Answer: a) Linearity, homoscedasticity via residuals
Explanation:
Scatter of residuals vs fitted predicts assumptions.
72. Polychoric correlation for
Correct Answer: a) Ordinal variables
Explanation:
Assumes underlying continuous latent variables.
73. In EDA, melting data changes
Correct Answer: a) Wide to long format
Explanation:
Facilitates plotting multiple series.
74. SHAP values in EDA preview
Correct Answer: a) Feature contributions post-model
Explanation:
Explains individual predictions for interpretability.
75. For survival data EDA, Kaplan-Meier estimates
Correct Answer: d) All of the above
Explanation:
Non-parametric curve for time-to-event analysis.
76. A sunburst plot visualizes
Correct Answer: a) Hierarchical data
Explanation:
Nested rings show proportions in categories.
77. In EDA, Levene's test checks
Correct Answer: a) Equal variances
Explanation:
Robust to non-normality for ANOVA assumptions.
78. Treemap displays
Correct Answer: a) Proportional areas for categories
Explanation:
Rectangles sized by value in hierarchical layout.
79. EDA for clustering previews with
Correct Answer: a) Elbow method on k-means
Explanation:
Plots inertia vs k to suggest optimal clusters.
80. Biserial correlation for
Correct Answer: a) Continuous and binary variables
Explanation:
Point-biserial if binary is true dichotomy.
81. In EDA, pivot_longer in R or melt in Python
Correct Answer: a) Reshapes wide to long
Explanation:
Prepares tidy data for analysis.
82. LIME explains
Correct Answer: a) Local model interpretations
Explanation:
Approximates black-box models locally with interpretable ones.
83. For network data EDA, use
Correct Answer: a) Graph visualizations like node-link
Explanation:
Shows nodes and edges for connectivity patterns.
84. Anderson-Darling test assesses
Correct Answer: a) Goodness-of-fit to distribution
Explanation:
Sensitive to tail deviations from normal.
85. Sankey diagram illustrates
Correct Answer: a) Flow between categories
Explanation:
Width proportional to magnitude in multi-stage processes.
86. EDA for classification includes
Correct Answer: a) Class separation via LDA plot
Explanation:
Linear Discriminant Analysis projects for discriminability.
87. Tetrachoric correlation assumes
Correct Answer: a) Binary data from underlying continuous
Explanation:
For dichotomous variables implying latent scale.
88. In EDA, dcast or pivot in tools
Correct Answer: a) Long to wide reshaping
Explanation:
Spreads variables for certain summaries.
89. Counterfactual explanations in EDA show
Correct Answer: a) What-if scenarios for predictions
Explanation:
Alters features to see outcome changes.
90. For audio data EDA, spectrograms visualize
Correct Answer: a) Frequency over time
Explanation:
2D representation of signal spectrum.
91. Kolmogorov-Smirnov test compares
Correct Answer: a) Distributions
Explanation:
Maximum difference in empirical CDFs.
92. Alluvial plot shows
Correct Answer: a) Changes in category proportions over stages
Explanation:
Like Sankey but for categorical shifts.
93. In EDA for anomaly detection, isolation forest previews
Correct Answer: a) Anomaly scores
Explanation:
Path length in trees indicates isolation.
94. Phi coefficient for
Correct Answer: a) 2x2 contingency association
Explanation:
Pearson's r for binary variables.
95. Gather function in tidyverse
Correct Answer: a) Wide to long
Explanation:
Tidy data principle for analysis.
96. Anchored explanations focus on
Correct Answer: a) Comparison to baseline prediction
Explanation:
Highlights feature impacts relative to reference.
97. For image data EDA, use
Correct Answer: a) Pixel histograms or t-SNE embeddings
Explanation:
Visualize color distributions or latent spaces.
98. Shapiro-Wilk test for
Correct Answer: a) Normality
Explanation:
Powerful for small samples.
99. Chord diagram visualizes
Correct Answer: a) Interconnections between categories
Explanation:
Arc segments with linking ribbons.
100. EDA for recommendation systems includes
Correct Answer: a) User-item matrix sparsity
Explanation:
Percentage of missing interactions.
101. Contingency coefficient for
Correct Answer: a) Categorical association beyond 2x2
Explanation:
Chi-square based, asymmetric.
102. Spread function in R
Correct Answer: a) Long to wide
Explanation:
Pivots values into columns.
103. Prototype-based explanations use
Correct Answer: a) Nearest neighbors as exemplars
Explanation:
Shows similar cases for context.
104. For video data EDA, frame sampling and
Correct Answer: a) Optical flow analysis
Explanation:
Motion vectors between frames.
105. Jarque-Bera test combines
Correct Answer: a) Skewness and kurtosis for normality
Explanation:
Omnibus test against normal.
106. Parallel sets plot for
Correct Answer: a) Multi-category flows like alluvial
Explanation:
Ribbon bands for proportions.
107. In reinforcement learning EDA, check
Correct Answer: a) State-action distributions
Explanation:
Exploration coverage in environments.
108. Lambda coefficient for
Correct Answer: a) Asymmetric nominal association
Explanation:
Predictive reduction in error.
109. Unpivot in data tools
Correct Answer: a) Wide to long
Explanation:
Standardizes column structure.
110. Subgroup explanations in EDA target
Correct Answer: a) Specific data slices
Explanation:
Tailored insights for segments.
111. For graph data EDA beyond basics, centrality measures like
Correct Answer: a) Degree, betweenness
Explanation:
Node importance in networks.
112. D'Agostino's K-squared test for
Correct Answer: a) Normality via skew and kurtosis
Explanation:
Asymptotic chi-square.
113. Mosaic plot for
Correct Answer: a) Categorical contingency visualization
Explanation:
Tiled bars for associations.
114. EDA in causal inference previews with
Correct Answer: a) DAGs for confounding
Explanation:
Directed Acyclic Graphs map relationships.
115. Uncertainty coefficient for
Correct Answer: a) Nominal predictive association
Explanation:
Entropy-based, asymmetric.
116. Pivot_table in pandas for
Correct Answer: a) Multi-index aggregation
Explanation:
Flexible crosstabs with functions.
117. Contrastive explanations compare
Correct Answer: a) Prediction to counterfactual
Explanation:
Minimal changes for outcome flip.
118. For tabular data EDA, automated tools like
Correct Answer: a) Pandas Profiling
Explanation:
Generates comprehensive HTML reports.
119. Lilliefors test is a
Correct Answer: a) KS variant without specified distribution
Explanation:
For normality, parameters estimated from data.
120. Dot plot alternative to
Correct Answer: a) Bar for small categories
Explanation:
Points on axis for frequencies.
121. In federated learning EDA, focus on
Correct Answer: a) Local dataset summaries without sharing
Explanation:
Preserves privacy in distributed settings.
122. Goodman-Kruskal gamma for
Correct Answer: a) Ordinal association
Explanation:
Accounts for tied pairs in ranks.
123. Reshape in Python for
Correct Answer: a) Data format changes
Explanation:
Stack, melt, pivot for tidy data.
124. Input gradient explanations use
Correct Answer: a) Model derivatives w.r.t. input
Explanation:
Sensitivity of prediction to features.
125. For sensor data EDA, time-frequency analysis like
Correct Answer: a) Wavelet transforms
Explanation:
Localizes events in time and scale.
126. Cramér-von Mises test for
Correct Answer: a) Goodness-of-fit
Explanation:
Integral of squared CDF differences.
127. Streamgraph for
Correct Answer: a) Stacked area over time
Explanation:
Centered for flowing appearance.
128. EDA in A/B testing checks
Correct Answer: a) Group balance and power
Explanation:
Pre-test for valid comparisons.
129. Kappa coefficient for
Correct Answer: a) Inter-rater agreement beyond chance
Explanation:
For categorical ratings.
130. Tidy data principles in EDA ensure
Correct Answer: a) One variable per column, observation per row
Explanation:
Facilitates manipulation and analysis.
131. Guided backpropagation for
Correct Answer: a) Salient feature visualization in images
Explanation:
Modifies gradients for positive relevance.
132. For financial time series EDA, candlestick charts show
Correct Answer: a) OHLC prices
Explanation:
Open, High, Low, Close for volatility.
133. Anderson-Rubin test in
Correct Answer: a) Instrumental variable strength
Explanation:
Weak instrument detection.
134. Waffle chart for
Correct Answer: a) Proportional parts like pie alternative
Explanation:
Grid squares for percentages.
135. EDA for NLP includes
Correct Answer: a) Token length distributions, vocab size
Explanation:
Text-specific summaries.
136. Yule's Q for
Correct Answer: a) 2x2 table association
Explanation:
Dichotomous measure from odds ratio.
137. Stack in pandas for
Correct Answer: b) Columns to rows
Explanation:
Longer format from wide.
138. Layer-wise relevance propagation for
Correct Answer: a) Deep net heatmaps
Explanation:
Backpropagates relevance scores.


