If you're seeing this message, it means we're having trouble loading external resources on our website.

If you're behind a web filter, please make sure that the domains *.kastatic.org and *.kasandbox.org are unblocked.

### Course: Statistics and probability>Unit 2

Lesson 3: More on data displays

Misleading Line Graphs. Created by Sal Khan and Monterey Institute for Technology and Education.

## Want to join the conversation?

• What is the easiest way to create a misleading graph?
• The easiest way to create a misleading graph is not to label the X and Y axes. If you leave off all numbers on the sides, then people will assume that two graphs have the same scale. Or that a graph (measuring one month that looks good) in a news story talking about something over a whole year will be assumed to be measuring the year in the story, not just a month.
• Is scale the easiest way to mislead a graph?
• Yes. Change the scale so that it seems one graph is worse.
• Do we use misleading graphs in modern day life?
• You would be surprised how often they are used in politics, marketing, et cetera. https://www.youtube.com/watch?v=1F7gm_BG0iQ
• How can you tell what the exact answer is with graphs?
• Mostly the graphs are not used to tell you the exact numbers, they are used to show correlation between things or to show development of things in time.
If you want exact answers you mostly look for them in tables from which you have created graphs.
• Why would anyone want to draw a misleading line graph?
(1 vote)
• 1. To mislead people. If people want to convince others, they can argument for their cause using data which not exactly support their cause, but look as if they did if presented in the 'right' way. They are not exactly lying about the facts in that case, but present them in a very biased way. For example when you want convince people of the benefits/downsides of a certain policy, the importance of some scientific results or the success of a buisness strategy. Or, in advertisement, to convince people of buying a product, Basically whenever it's about selling the data for some kind of benefit, this might happen.

2. Unintentionally. This might also happen unintentionally. If you present your data about, say a project to somebody, you choose a certain way to display it. This way you may choose because of convenience, because you want to emphasize a certain point or for any other reason without malintent. However, as you know your data very well, you might not recognize that you display your data in a misleading way, as for you all the information in it is obvious, whereas for other people, it is not and they will therefore more likely be misled by some aspects of the graph you choose.
• At Sal said Thrill Cola but it's actually Thrill Soda
• who was the first person to think of the line graph?
• William Playfair was the first person to think of the line graph
• Why do people not completely evaluate a graph to make sure it is not misleading? Why does everyone like to see things go up?
• Misleading graphs may be created intentionally to hinder the proper interpretation of data to argue/convince the people about something that supports them or accidentally due to unfamiliarity with graphing software, misinterpretation of data, or because data cannot be accurately conveyed. Misleading graphs are often used in false advertising like the one Sal said in the video

Maybe because people are too lazy, I guess

Not just going up, it can go down too. Here's an example:
When people *glance*at a graph, they see that product A is rising and product B is falling and currently, A is better than B, which is not so they think that A is better than B, which supports the graph maker's favor.

Or when people glance at another graph, it shows that city A has lots of gunfights, which is not. The people think that city A is very violent, which is not which supports the graph maker's favor.

I hope this helps :)
(1 vote)
• Are there any activities for misleading line graphs?