AKA: Stacked Bar Charts, Segmented, Composite, Component, Compound [Bar Graphs]
Why: stacked bar graphs (SBG) show the quantitative relationship that exists between a main category and its subcategories. Each bar represents a principal category and it is divided into segments representing subcategories of a second categorical variable. The chart shows not only the quantitative relationship between the different subcategories with each other but also with the main category as a whole. They are also used to show how the composition of the subcategories changes over time.
These kind of charts enable us to show more complex relationships than those usually done with standard bar graphs (https://medium.com/nightingale/bar-graphs-why-how-8c031c224c9f). Stacked Bar Graphs should be used for Comparisons and Proportions but with emphasis on Composition. This composition analysis can be static -for a certain moment in time- or dynamic -for a determined period of time-.

#data-science #stacked-bar-chart #bar-graph #data-visualization #storytelling