•Why bar and pie graphs

suck and line graph rules.

•Why bar and pie graphs

suck and line graph rules.

lack

Bar graphs only show counted objects.

Not useful for finding connections between variables.

Pie (circle) graphs show the parts of the same whole, in percentage form.

Not useful for finding connections between variables.

Line Graph Rules

1. Give your graph a title of “dependent variable” versus “independent variable”. This goes neatly at the top and middle of the graph (not necessarily of the piece of paper).

2. Label each axis and indicate the units used. The independent variable always goes on the x-axis and the dependent variable always goes on the y-axis.

3. Number the axes in equal increments. You don’t have to label every line, but don’t change the amount of spacing of each successive line. Your scale should cause the graph to take up as much (at least 60%) of the graph paper as possible. You do not always have to start the origin at (0,0). Consider each time if it is appropriate or not for that particular graph.

DO NOT DO THIS, EVER!

4. Locate the data points you place on a graph with an “X” or a dot with a circle around it. This allows the points to be easily seen once the line is drawn.

YES

YESNO

5. All line graphs should use best-fit lines that are either a straight line (use a straight edge) or a smooth curve (free-hand carefully). Your data should indicate which type of line to use.

Never use a connect-the-dots line. Your line does not have to go through all your data points (but get it close). This shows the uncertainty associated with each measurement, and takes an average of the data.