How to identify Graphs that have tricks in them which mislead us.

1. Image Source: http://www2.fiu.edu

2. The most common “trick” with graphs is to
make the scale not start at zero.
This makes small differences look much bigger.
Image Source: http://thinkingmeat.net

3. Sometimes the Scale does not start at zero,
and the Graph is also put in a 3D perspective
which confuses our eyes.
Image Source: http://www.math6.org

4. Image Source: http://www.his.washk12.org/

5. The Scale does not start at zero, and makes the house
price in 2006 look about seven times higher than 1975,
when it is really only about two and a half times higher.
(eg. 160 000 in 2006 is about 2.5 times 60 000 in 1975).
Image Source: http://www.brickonomist.net

6. In Picture Graphs, the items are sometimes all made
different sizes to trick our eyes into thinking we have
more of the bigger sized items.
Image Source: http://www.bbc.co.uk

7. In this Picture Graph, the year 2000 picture is about
eight times bigger than the 1960 image. However
when we check on the vertical scale, year 2000 is only
two and a half times bigger. (2.5 x 100 = 250).
Image Source: http://www.yale.edu

8. Trick or Treat ? In this Picture Graph, there is
definitely a trick being done! From the vertical scale
Michael collected about twice as much candy as
Shayna, but his picture is about three times bigger.
Image Source: http://www.yale.edu

9. This pie chart is totally incorrect. The sizes of the
pieces of pie have not been drawn the right sizes.
Image Source: http://www.visionjar.com

10. This non-standard pie chart is interesting. If
“Cartera” was graphed properly as a piece of pie, then
it would only be a very thin slither, and not nearly as
big looking as the big circle drawn for it here.
Image Source: http://dribbble.com

11. In this non-standard chart, it is very hard to work out
what point they are trying to make or explain.
Image Source: http://image.bayimg.com

12. The common ways to make a graph misleading are:
• Scale not starting at zero.
• Scale made very small to make graph look very big.
• Scale values or labels missing from the graph.
• Incorrect scale placed on the graph.
• Pieces of a Pie Chart are not the correct sizes.
• Oversized volumes of objects that are too big for
the vertical scale differences they represent.
• Size of images used in Pictographs being different
for the different categories being graphed.
• Graph being a non-standard size or shape.

13. Is this a
Misleading
Graph ?
Image Source: http://mathspig.files.wordpress.com

14. http://passyworldofmathematics.com/