Stage 5 Year 9 Misleading Graphs Press CtrlA

Stage 5 Year 9 Misleading Graphs Press Ctrl-A © 2009 – Not to be sold/Free to use

Misleading Graphs Massive Increase In House Prices this Year 82 000 81 000 80 000 1998 1999 Year Average House Price Displaced Axes 80 000 60 000 40 000 20 000 0 1998 1999 Year The increase in price was not as big as it appeared to be. 2

Misleading Graphs Displaced Axes 1000 995 900 990 800 Number of Votes 1000 985 980 975 970 700 600 500 400 965 300 960 200 955 100 950 Pizza Hot Dogs Hamburgers Favourite Food The number of votes appears significantly here. 0 Pizza Hot Dogs Hamburgers Favourite Food The number of votes appears not so significantly here. 3

Misleading Graphs Exaggerated use of Area or Volume. Number of Singles Sold 996 1 5 199 Number of Singles Sold 998 1 1997 1995 1996 1997 1998 The Brown column looks bigger than the purple column. But is it? . 4

Misleading Graphs The Exaggerated use of Area or Volume. Key: 50 Dog: Cat: Horse: 50 50 This is bad. Dog: various sized The pictures distorts Cat: the graph. Horse: This is much better All pictures must be the about the same size. (Area) 5

Misleading Graphs Exaggerated use of Area or Volume. Sales at Gerry’s Milkbar have doubled from 2007 to 2008. 2007 2008 The 2008 volume is eight times bigger than the 2007 volume. 6

Misleading Graphs Irregular Scale Axes 1993, 1996 and 1998 are missing. 7

Misleading Graphs Irregular Scale Axes 1993, 1996 and 1998 are added. 8