Less is more with bar graphs

Updated: Nov 13, 2018

How many times have your eyes glossed over during a presentation because a graph is too small or it doesn't make sense? By making small changes such as simplifying the data, increasing the size of the graph, telling a story with the title, and removing the legend, this helps the viewer stay engaged with the presentation and interpret the important data in a short amount of time.


A client recently asked me to update their bar graphs for a powerpoint presentation. Often times when editing graphs, making small changes can go a long way. This post shows an example of some changes I make to graphs being used in powerpoint presentations. Here is the original graph:


Source: United Nations, Department of Economic and Social Affairs, World Population Prospects: 2012 Revision, June 2013, http://esa.un.org/unpd/wpp/index.htm


When considering what graph to use and what data to highlight, it is important to consider who the audience is and how they will be interacting with the graph. In this case, the graphs are meant for powerpoint presentations, so the audience would not necessarily have the graph right in front of them to examine on paper.


Here are the 4 steps I took to enhance the graph on this powerpoint slide:

1. Reduce the amount of information in the graph

2. Increase size of the graph bars and text

3. Title=Story

4. Use color to embed the legend in the title



1. Reduce the amount of information in the graph. A client might decide only some of the countries in this graph are relevant to this presentation, so I would reduce the number of countries included to help make the graph more readable. If the data isn't relevant or interesting to your audience, you have to ask yourself why you are presenting it.


2. Increase size of the graph bars and text. Since this graph was going to be used on a powerpoint slide, I increased the size of the bars and all the text in the graph, so the audience could see it from far away. This would be less of a concern if it was being designed for a print or web document.


3. Story=Title. When showing an audience a graph, often times it is best practice to put the story or thesis of the graph in the title, doing the hard work for them. I changed the title to "People ages 65+ will make a higher percentage of the population in 2050 compared to 2010.


4. Use color to embed the legend in the title. By embedding the legend in the title, the viewer can more easily move their eyes directly from the title to the bars in the graph. It removes the unnecessary step of processing the contents of a legend. I also chose more contrasting colors so the viewer can easily tell the difference when comparing the two years in the data.


Here is the updated graph:


Source: United Nations, Department of Economic and Social Affairs, World Population Prospects: 2012 Revision, June 2013, http://esa.un.org/unpd/wpp/index.htm


Because this graph is only being used in a powerpoint presentation, I might present the client with another option to further simplify the data since the viewer will only have a short time to interpret the data. If the trend of increasing population percentages of people over age 65 is consistent across all relevant countries, the client might consider showing just the average worldwide. However, either graph would be effective.


Here is that more simplified version:



Source: United Nations, Department of Economic and Social Affairs, World Population Prospects: 2012 Revision, June 2013, http://esa.un.org/unpd/wpp/index.htm



© Sara DeLong