Over the course of your research, you're likely to come across lots of charts and graphs. It's important to read them closely, not only to understand what information they're trying to communicate, but to also identify the ones that are misleading.
Misleading charts and graphs are the result of either unintentional distortion because the author doesn't understand how to properly present the data, or intended deception because the author wants to give the reader the impression that the data is either worse or better than it really is.
Below you will see a series of misleading charts and graphs with a short explanation of the kind of deception used.
One of the most common ways that graphs are intentionally made misleading is by exaggerating the scale on the y-axis. Graphs should have a baseline on the vertical scale (y-axis) that starts at zero. When the author zooms in on that scale, for example, starting at 50 on a scale of 100, it can make even minor changes appear dramatic.
This example from 2012 has many things that make it problematic, but the most obvious is the scale: It goes from 94 million to 108 million; a difference of only 14. It has been crafted to appear that the increase in Americans on welfare is exploding when in reality, the increase represents 15% over two years.
This line graph shows a steady decrease in average temperature for Boston, Massachusetts for a 14-year period. Can you spot the problem?
GLOBAL WARMING IS A MYTH!
If you caught the fact that this graph is showing only half of the year, then you're exactly right! It's showing average temperatures for the months between July and December, so you would naturally expect temperatures to fall as summer moves toward winter. In addition to that, this graph has averaged the highs and lows together, and then averaged those numbers over 14 years giving an incomplete picture of temperature fluctuations.
This graph from a Reddit poster in 2014 seemingly shows that the number of murders committed with firearms dropped dramatically after Florida passed its "Stand Your Ground" law in 2005. But notice how the y-axis has been flipped so that zero is at the top and the numbers increase as you look down the left side.
Here is the same graph with the y-axis in the correct position:
