A stacked bar chart is a type of data visualization used to display a categorical variable’s distribution over a set of discrete, typically qualitative, subcategories. It shows how a whole category is divided into subcategories and how each contributes to the total. Stacked bar charts are often employed in data analysis and presentation to illustrate the composition or breakdown of a data set.
How stacked bar charts work:
- Categories: On the x-axis of the chart, there are different categories or groups. These can represent anything from time periods, geographical regions, product types, or any other categorical data.
- Subcategories: Each category is further divided into subcategories, and each subcategory is represented as a segment of the bar. The length or height of the segment is in proportion to the quantity or percentage it represents within that category.
- Stacking: The segments for each category are stacked on top of one another, creating a bar for each category. This stacking makes it easy to compare the total size of the bars and the relative contribution of each subcategory within each category.
- Color Coding: Each segment is typically assigned a distinct color to differentiate between subcategories. The use of color coding helps viewers quickly understand the composition of the data.
Stacked bar charts are excellent for displaying part-to-whole relationships, highlighting the relative contributions of subcategories within categories, and showing how the composition of data changes across different categories. However, they can become challenging to interpret when you have too many subcategories or when there’s a lot of data, as the visual representation can become cluttered.
List of recommended resources #
For a broad overview #
How To Create a Stacked Bar Chart? [+ Examples]
This Venngage blog post gives a brief overview of stacked bar charts, their uses, and how to use them.
The efficacy of stacked bar charts in supporting single-attribute and overall-attribute comparisons
This paper analyzes the visualization method of stacked bar charts for presenting multiple attributes of data and assesses their efficacy in supporting attribute-comparison tasks.
For in depth understanding #
Data Visualisation: A Handbook for Data Driven Design
This book by Andy Kirk gives an extensive understanding of various data visualization techniques, providing a step-by-step thorough explanation.
Effective Data Visualization: The Right Chart for the Right Data
Written by Stephanie D. H. Evergreen, this comprehensive how-to guide shows readers how to create Excel charts and graphs that best communicate their data findings.
Case study #
This paper studying air quality on the east coast of Peninsular Malaysia makes use of stacked bar charts, a type of composition chart, to show the average mass composition of water-soluble ions in aerosol collected at the Bachok research station and the percentage of non-sea-salt and sea salt fractions of Ca 2+ , K + , Na + and SO 2− 4.
This paper makes use of stacked bar charts to summarize the microbial community composition of the leachate and river samples based on the MAGs taxonomically placed on the concatenated ribosomal protein tree.
References #
A Complete Guide to Stacked Bar Charts
