Draw a box on the poster board using a ruler. The box should cover most of the board, as it needs to be large enough for people to see from a small distance.
Write a title for your graph at the top. You might write, "The Effectiveness of Carpet Stain Removers."
Measure equal units along the left side of your graph and mark the intervals. Mark the bottom left corner of the graph as "0." Label the other intervals "1," "2," "3" and "4."
Write the names of the carpet stain removers at the bottom of the graph, spaced evenly apart.
Write a "key" underneath the graph that explains the numbers. For instance, you might write, "0 = no stain removal; 1 = slight lightening of stain; 2 = moderate lightening of stain;
3 = significant lightening of stain; 4 = total stain removal."
Draw a rectangle with the ruler that extends from the bottom of the graph to the appropriate score for that stain remover. For example, if Stain Remover X completely removed a soda stain, you would draw a rectangle from the bottom line above "Stain Remover X" to the number 4.