When you’ve got a large volume of quantitative information to present, charts are almost always your best way to go. Figures are much easier to make sense of when presented graphically. Whether your purpose is to compare, show relationships or highlight trends, charts let your audience visualize your message. Take a look at this Google Slides bundle of charts.
What can be confusing for you, though is which chart type to use. There are so many options! Which will work best – clustered columns, or stacked columns? Area graphs or line graphs? To help make the selection process easier, we’ve prepared a series of posts on the subject. In this and subsequent articles, we’ll examine common chart issues facing presenters, and how to solve them.
Let’s begin with a look at the difference between column charts and bar charts.
Column or Bar Charts?
Both column and bar charts have the same basic function: to visualize data that varies over a period of time, and comparisons among similar items. The types vary in the way they represent data. Column charts, obviously, use vertical columns (usually rectangles or cylinders). Bar charts are very similar, but arranged horizontally. Which orientation is better? That depends on two things: topic and readability of labels.
If you’re presenting quantitative data on a topic that has an element of direction, go with that direction in your choice of chart type. For instance, if you plan to compare the heights of the world’s tallest buildings, a column chart is the natural winner. Other topics that would favor column charts include sales projections, profits and losses, and trends. People naturally associate such concepts with upward or downward (vertical) images.
On the other hand, if you’re presenting the distances traveled by different drivers over a period of time, a bar chart would be the more natural choice. Again, it’s a matter of mental association. The concept of distance traveled is normally oriented horizontally. Other topics that lend themselves to bar chart representation include time, performance, and project management.
#2: Readability of Labels
If the topic doesn’t have any intuitive directional association, you can use either a bar or a column chart. Almost all slide presentations have a horizontal (“landscape”) layout, so the longer axis should run along the bottom of the chart, like this:
The length of the labels is another consideration. Longer labels are usually best presented on the side axis, for better readability:
Change Chart Types
When in doubt about which chart orientation is better for your data, remember that PowerPoint gives you the option to change chart types easily, without having to re-enter values. Explore your choices and settle on the chart that best fits your topic and audience.