How to Create a Two-Sided Y-Axis Graph

Arrange your data into columns and label each column. If you were evaluating five new hammer prototypes on ease of use and cosmetic appearance, for example, you would have the data arranged in three columns: Hammer Type, Ease of Use and Cosmetic Appearance. Use one row per variable measured.

Draw a horizontal line on graph paper to represent your x-axis. In this example, you are measuring five hammer types, so you would put five tick marks -- one for each hammer prototype tested.

Draw a vertical line on the left side of the x-axis. The line should begin at the point where the x-axis begins. Scale the line according to the range of values in your first y-variable. In this example, if ease of use is measured on a 10-point scale, the lowest value on the y-axis is "1" and the highest is "10."

Mark a dot or other symbol to demarcate each data point in the data set. For example, if Hammer 1 was ranked a "5" in terms of ease of use, you would located the intersection of the Hammer 1 tick mark on the x-axis and the y-value of "5" and put a dot at this point. In this example, you would have five dots. You can connect the dots with a line to show the relationships between the data points.

Draw another vertical line beginning at the far right edge of the x-axis and extending upward. Make the second vertical line equal to the first in length. This second vertical line represents your second y-variable; in this example, cosmetic appearance.

Mark the scale for the secondary y-axis by calculating the range of values for this variable. In this example, cosmetic appearance is rated on a 10-point scale, so the lowest point on this axis is "1" and the highest is "10."

Locate the intersection between the x-axis and the secondary y-axis value for each data point. In this example, if Hammer One was rated as a "7" in terms of cosmetic appearance, find the intersection between the tick mark on the x-axis that represents Hammer One and the value on the y-axis that represents "7." Mark these intersections with a star, bar or another symbol different than the one you used to mark the first y-axis data points to differentiate the variables.