Exploratory Data Analysis Techniques Flashcards
7 cards from real DSE practice questions. Tap to flip, then mark Knew It or Still Learning — missed cards come back until you master them.
Read the first 7 Exploratory Data Analysis Techniques flashcards as text
Which statistical measure is most resistant to the influence of outliers?
Answer: Median
The median is resistant to outliers because it depends only on the middle value(s) of the sorted data, not the magnitude of extreme values.
A violin plot combines features of which two visualizations?
Answer: Box plot and kernel density estimate
A violin plot shows a box plot inside a mirrored kernel density estimate, providing both summary statistics and the full distribution shape.
When exploring a dataset with 50 variables, which technique is most useful for quickly identifying correlated pairs?
Answer: Correlation heatmap
A correlation heatmap color-encodes all pairwise correlations in a compact grid, making patterns across many variables immediately visible.
What does a Q-Q (quantile-quantile) plot primarily assess?
Answer: Whether a dataset follows a theoretical distribution
A Q-Q plot compares the quantiles of observed data against the quantiles of a theoretical distribution; points near the diagonal line indicate a good fit.
Which of the following best describes 'data binning' in EDA?
Answer: Grouping continuous values into discrete intervals
Binning converts continuous variables into discrete categories (bins) to simplify analysis and reduce noise.
In a right-skewed distribution, which ordering of summary statistics is correct?
Answer: Mode < Median < Mean
In a right-skewed distribution the long tail pulls the mean up above the median, which sits above the mode.
What is the primary purpose of jitter in a strip plot?
Answer: To reduce overplotting by adding small random offsets to points
Jitter adds small random noise to point positions so that overlapping points become distinguishable, revealing the true density of observations.