How to spot a misleading graph (Vol.1)

A toothpaste brand claims their product will destroy more plaque than any product ever made. A politician tells you their plan will create the most jobs. We’re so used to hearing these kinds of exaggerations in advertising and politics that we might not even bat an eye.

But what about when the claim is accompanied by a graph? After all, a graph isn’t an opinion. It represents cold, hard numbers, and who can argue with those? Yet, as it turns out, there are plenty of ways graphs can mislead and outright manipulate. Here are some things to look out for.

In this 1992 ad, Chevy claimed to make the most reliable trucks in America using this graph. Not only does it show that 98% of all Chevy trucks sold in the last ten years are still on the road, but it looks like they’re twice as dependable as Toyota trucks.

That is, until you take a closer look at the numbers on the left and see that the figure for Toyota is about 96.5%. The scale only goes between 95 and 100%. If it went from 0 to 100, it would look like this.

This is one of the most common ways graphs misrepresent data, by distorting the scale. Zooming in on a small portion of the y-axis exaggerates a barely detectable difference between the things being compared. And it’s especially misleading with bar graphs since we assume the difference in the size of the bars is proportional to the values.

So the next time you see a graph, don’t be swayed by the lines and curves. Look at the labels, the numbers, the scale, and the context, and ask what story the picture is trying to tell. Look out for more tips on reading graphs coming later this week!

From the TED-Ed Lesson How to spot a misleading graph - Lea Gaslowitz

Animation by Mark Phillips

“Show me instead." 

i say this every time, but seriously… read @tyranttortoise‘s Skeleton Squatters and the Landlady. this latest chapter is one of only innumerable reasons why it is forever in my top favorite fics, period.

… and talk about seeing fireworks with a kiss. <333 honestly red is my eternal weakness, and i’m not even mad about it.

This is how scientists think birds see the Earth’s magnetic field.

See how the black patches align over certain areas? That dark patch at the base of their vision shows South, with the reverse indicating North. Researchers think this might be how birds like pigeons can use magnetic fields to navigate.

Here’s how it works: there’s a protein in their eyes called cryptochrome. When blue light hits it, it becomes active, and stays active for a little while. How long it stays active for, though, depends on the Earth’s magnetic field, and since cryptochrome is known to affect the sensitivity of the birds’ retinas to light, we think this is the effect it has on their vision.

We have this very same molecule in our eyes, but the molecule that lets it stay active for long enough to be affected by the magnetic field, superoxide, is toxic, so the antioxidants in our eyes lock it down too quickly.  Researchers think we’ve traded longevity for magnetovision.

Want to know more? We made a whole video answering the question, do blind birds can navigate!? Watch it here: