Final answer:
Side-by-side bar graphs present multiple bars for each category for direct comparison, while segmented bar graphs show contributions to the whole within each category by segmenting the bars internally. The choice between these and other graphs, like line graphs or pie charts, depends on the data and the presentation objective.
Step-by-step explanation:
The bars in a side-by-side-bar graph and those in a segmented bar graph serve to display categorical data for comparison. However, they do this in different ways. In a side-by-side-bar graph, each category (such as countries or years) has its own set of bars placed next to each other for direct comparison of the values, with a common scale on the vertical axis representing numerical or percentage values. Segment bar graphs, on the other hand, display each category as a single bar which is internally divided into segments representing subcategories or parts of the whole, also aligned with a numerical or percentage scale on the vertical axis.
This distinction becomes essential when deciding which graph to use for data presentation. While a side-by-side bar graph might be better for highlighting differences between groups, segmented bar graphs are useful for illustrating how different parts contribute to the whole within each group. The choice between using these and other types of graphs, such as line graphs or pie charts, would depend on the nature of the data and what aspect of the data you wish to emphasize.