As data journalism has its moment in the media, a reminder that we bring our own assumptions to the reading of charts and graphs.

(Photo: LHF Graphics/Shutterstock)

At Junk Charts, Kaiser Fung drew my attention to a graph released by Reuters. It is so deeply misleading that I loathe to expose your eyeballs to it. So, I offer you this:

The original figure is on the left. It counts the number of gun deaths in Florida. A line rises, bounces a little, reaches a second highest peak labeled “2005, Florida enacted its ‘Stand Your Ground’ law,” and falls precipitously.

What do you see?

This example is a great reminder that we bring our own assumptions to our reading of any illustration of data.

Most people see a huge fall-off in the number of gun deaths after Stand Your Ground was passed. But that’s not what the graph shows. A quick look at the vertical axis reveals that the gun deaths are counted from top (0) to bottom (800). The highest peaks are the fewest gun deaths and the lowest ones are the most. A rise in the line, in other words, reveals a reduction in gun deaths. The graph on the right—flipped both horizontally and vertically—is more intuitive to most: A rising line reflects a rise in the number of gun deaths and a dropping a drop.

The proper conclusion, then, is that gun deaths skyrocketed after Stand Your Ground was enacted.

This example is a great reminder that we bring our own assumptions to our reading of any illustration of data. The original graph may have broken convention, making the intuitive read of the image incorrect, but the data is, presumably, sound. It’s our responsibility, then, to always do our due diligence in absorbing information. The alternative is to be duped.

This post originally appeared on Sociological Images, a Pacific Standard partner site, as “How to Lie With Statistics: Stand Your Ground and Gun Deaths.”