GRAPHING DATA CHECKLIST

STEPS TO FOLLOW:                                                                                            Printable Version of page

1. Obtain a piece of graph paper - never use plain paper or ordinary  
     lined paper for graphs.
         2. Decide what information will go on the abscissa (X-axis, horizontal axis)
             and what information will go on the ordinate (Y-axis, vertical axis).
             a. If the problem tells you what to put where, do so.
             b. If you must decide: Put the dependent variable on the Y-axis and the
                 independent variable on the X-axis.
        3. Place a zero at origin of graph. The origin is the junction of the X and
            Y-axes. (Note: This is not appropriate for all graphs, but will be many
            of the graphs we will run into here).
        4. Examine the data values for the X-axis. What is the biggest number you
             must "squeeze" onto the graph? Decide the value of one space on the
            graph (maybe one space = 1 g. or one space = 5 g.) Decide on
            appropriate spacing by considering the following:
               a. You must be able to plot all of your values.
               b. Your graph must cover as much of the page as possible.
               c. Decimal values should be easy to plot. (For example, if you let one
                space equal 3 grams, you would have a hard time trying to plot 3.34
                grams.)

            Do similar reasoning for the Y-axis.

            NOTE: As you look at the X-axis, each space must be of equal value.
            Same for the Y-axis, although the spacing on the two axes need not be
            equal to each other.
         5. Put the numbers you have decided upon along the X and Y-axes. Place
             numbers on each axis so that they may be read without turning the
             paper. You do not need to label each division.
         6. Label each axis (temperature, time, or guys dated per month.) The label
            on the vertical axis should be placed so that it can be read when the
            paper is turned 90° clockwise.
         7. Put units on axes. (oC , grams, liters)
         8. Plot corresponding data values (one point, for each set of values). Make
             a small dot at the proper graph position to mark the point, and then
             surround the dot with a small circle so the point will not be lost.
             Triangles, squares, etc., can be used to surround points for a second,
             third, etc., line on the same graph.
         9. If the points lie along a straight line, use a ruler to draw an average line.
             If the points look more like a curve, draw in a smooth average curve
             using a French Curve or do it free hand with a smooth continuous curve.
             Do not just connect the dots. An average line is one where some
             points may fall above; others may fall below the line.
        10. Title the graph - usually at the top somewhere. The title should state in
              words, not abbreviations, the dependent variable as a function (vs) of
              the independent variable. Ex: Acceleration vs Time. Other relevant
              information may make your title more complete. Ex: Acceleration of a
              Ford Bronco on a Level Track vs Elapsed time at 25° C and 1 Atm
              Pressure
              

Sample graphs


        Acceleration vs Mass                                                 Acceleration vs Mass

                             

Figure 1a: Glider acceleration versus hanging mass for constant glider mass. Figure 1b: When the data points are connected by lines, a small amount of curvature becomes evident.

Cooling Curves: Temperatures of Benzophenone and Mixtures vs Time

Average Velocity of a Glider on an Inclined Airtrack as a Function of Time

 

Return to Toolbox    Printable Version of Page