I’m continually looking at information about church leaders and trying to figure out the best way to present it visually. “Should I use a pie chart, a bar graph, a line graph or something really specialized like a Venn diagram?” Too often I don’t have a clear path to what kind of graphic will communicate best.
This just-released book by expert Dona M. Wong, Wall Street Journal Guide to Information Graphics, has some very helpful answers. With over 500 illustrations to accompany its text, it both shows and explains. In many sections, it uses its left-hand page to show the wrong or unhelpful approach, and to explain why. The right-hand page is the better approach, with commentary on why.
* In general pie charts are for simple data with only a few numbers and which adds up to the equivalent of 100%. Line or bar charts do better for complex data.
* In pie charts start your biggest slice at the 12:00 position going clockwise. Place your second biggest slice at 12:00 going counterclockwise. Thus least important data goes in the 6pm to 9pm slot. Why? That’s how the eye typically goes and the brain understands best. Don’t exceed 5 slices; if you need more slices, use a segmented bar (rather than a pie within a pie) to show a breakdown of the fifth slice – see illustration at left.
* Vertical bar charts are easier to understand than horizontal ones. If bars are not all the same color, go light to dark (see illustration at right of zebra colors, which should be avoided). If you are making one point, put that bar in one color or shade and all the rest in another color.
* For bar charts (whether horizontal or vertical) the bar width should be roughly twice the length of the space between the bars.
* In line charts with multiple lines, use four lines maximum with the main line in a different color.
* Always build zero baseline into charts in order to represent proportionality appropriately.
Warren Bird, Ph.D., is Research Director at Leadership Network, and co-author of 21 books on various aspects of church health and innovation. His recent “Leadership Network” books blogs include What We’re Reading at Leadership Network, The Soviet Plot to Kill God, Hard Times for Publishers but Great Times for Readers, Migration and Churches in Europe, The Worst Moment in Most Church Services, Excellent Resources for Church-Based Grants, Multi-Site Church Roadtrip Released Today, Holy Mavericks, Don’t Let This Book Cover Fool You, Turning Your Idea into a Book and Do White Churches Hold Others in Cultural Captivity?