AML Data Analysis & Reporting 2 — Questions and Answers
Question 1: When analyzing a dataset with heavy right skew, which transformation is most commonly applied before modeling?
- Squaring the variable
- Log transformation (Correct answer)
- Min-max normalization
- One-hot encoding
Correct answer: Log transformation
Log transformation compresses large values and reduces right skew, making distributions more symmetric for modeling.
Question 2: In a confusion matrix for a binary classifier, which metric is computed as TP / (TP + FP)?
- Recall
- F1 Score
- Precision (Correct answer)
- Specificity
Correct answer: Precision
Precision measures the proportion of positive predictions that are actually positive: TP / (TP + FP).
Question 3: A data analyst notices that two features have a Pearson correlation of 0.98. What is the primary concern?
- Overfitting
- Multicollinearity (Correct answer)
- Data leakage
- Class imbalance
Correct answer: Multicollinearity
A near-perfect correlation between two predictors indicates multicollinearity, which can destabilize regression coefficient estimates.
Question 4: Which visualization is most appropriate for displaying the distribution of a continuous variable across multiple categories?
- Pie chart
- Scatter plot
- Violin plot (Correct answer)
- Heatmap
Correct answer: Violin plot
Violin plots combine a box plot with a kernel density estimate, effectively showing distribution shape across categories.
Question 5: In time-series analysis, what does the autocorrelation function (ACF) measure?
- Correlation between two separate series
- Correlation of a series with its own lagged values (Correct answer)
- Trend component magnitude
- Seasonal amplitude
Correct answer: Correlation of a series with its own lagged values
ACF measures the correlation between a time series and its own past values at various lag intervals.
Question 6: When creating a dashboard KPI report, which principle ensures that the most critical metric is immediately visible?
- Progressive disclosure
- Above-the-fold placement (Correct answer)
- Color gradient encoding
- Drill-down interactivity
Correct answer: Above-the-fold placement
Placing the most critical KPI above the fold ensures executives see it without scrolling, following dashboard design best practices.
Question 7: A feature importance report shows that 'customer_id' ranks as the top predictor. What does this most likely indicate?
- Customer ID is a strong signal
- The model has high bias
- Data leakage from a unique identifier (Correct answer)
- Overfitting due to low regularization
Correct answer: Data leakage from a unique identifier
A unique identifier ranking as top predictor typically signals data leakage, where the ID correlates with the target through improper data joining.
AML Data Analysis & Reporting 2
When analyzing a dataset with heavy right skew, which transformation is most commonly applied before modeling?