Categorical Data
Bar Chart
- Used to display frequencies or proportions of categorical variables
- Each bar represents a category with its height corresponding to frequency
- Easily compares values across different categories
Pie Chart
- Represents proportions as slices of a circle
- Useful for showing part-to-whole relationships
- Less effective for comparing similar values
Frequency Table
- Tabular summary of frequency and proportion
- Can be accompanied by bar chart or pie chart for visual representation
- Enhances understanding of distribution in categorical data
Numerical Data
Histogram
- Displays the distribution of a continuous numeric variable
- Bins group values into intervals with bar heights representing frequency
- Useful for identifying skewness, modality, and spread
Boxplot (Box-and-Whisker Plot)
- Visualizes median, quartiles, and potential outliers
- Shows distribution shape and variability
- Ideal for comparing multiple numeric groups
Density Plot
- Smoothed version of a histogram using a kernel function
- Visualizes the probability distribution of a continuous variable
- Useful for overlaying multiple distributions
Line Chart
- Typically used for time series or ordered data
- Shows trends, patterns, or changes over intervals
- Each point connected with lines to indicate progression
Multivariate Visualizations
Scatter Plot
- Displays relationship between two numeric variables
- Shows trends, clusters, and possible outliers
- Basis for correlation and regression analysis
Bubble Chart
- Extension of scatter plot with size of bubbles representing a third variable
- Adds one more dimension of data insight
- Useful in business and demographic visualizations
Faceted Plots
- Create multiple subplots by splitting data based on a categorical variable
- Useful for comparing distributions or relationships across categories
- Often used with histograms, scatter plots, or boxplots
Heatmap
- Color-coded matrix showing values of two variables (often categorical or correlation)
- Commonly used for visualizing correlation matrices or frequency tables
- Colors represent magnitude or intensity
Distribution Shape and Outliers
Histogram and Density Plot
- Enhances distribution interpretation by showing both bar and smoothed curve
- Ideal for understanding shape, central tendency, and spread
Boxplot with Outlier Labels
- Explicitly marks outliers beyond whiskers
- Helps in detecting unusual data points
Violin Plot
- Merges boxplot and density plot
- Reveals detailed distribution shape while showing summary statistics