The Guide to Great Graphs Ten things every graph needs! Or… Ten things we hate about graphs!

1. The Title Every graph needs an appropriate title. The title should be informative and should tell the reader about the information contained in the graph… For example - “My Graph” is a bad title because it tells us nothing, but “Graph showing the relationship between Age and weight of South American Polar Bears” prepares the reader for the information that they are viewing.

2. The proper type of graph Almost every graph you will complete in chemistry class will be a line graph or x- y scatter graph. They look like this:

3. Axis selection The independent variable (the one that you control) is placed on the x-axis and the dependant variable (the one that responds) should be placed on the y- axis. Decide, based on your experiment, which variable is dependant and which is independent, and begin to construct your axis.

4. A Proper scale A graph that is too small is difficult to read and a graph that is too big will not fit on the page. Your graph should fill at least ¾ of the page, this requires careful planning, to think carefully about your graph BEFORE labeling your axis.

5. Regular Intervals for units You should choose an appropriate scale for your axis, the intervals should be equally spaced and they should also be selected based on the range of your data. For example, given the data below, 1.5 m, 5.3 m, 2.6 m, 3.7m and 6.8m The best choice for your scale would be in intervals between.1 m and.5 m, based on the space available, or the number of squares on the graph paper. ALSO… the scale does not need to be the same on both axis.

6. Labels on Each Axis Every graph should have a label for each axis clearly marked. This allows the reader to gather all the information needed to interpret the graph.

7. Units for each Axis You should always include a unit for each axis. The unit should be written next to the label and placed in (parenthesis). This ensures that the graph will be correctly interpreted.

8. A Line of Best Fit You will not always need to include a line of best fit If there is a trend in your data it is usually appropriate to include a line of best fit. In chemistry, a line of best fit is not always a straight line. Sometimes it is curved. Also it does not always go through (0,0) (the origin.) Since we will be plotting experimental data the line of best fit won’t connect all the points, but it should show a general pattern in the points.

9. Your Name Every graph should have your name on it, along with the date and your class period. So we can give you the credit you deserve!

10. The Proper Materials Every graph that you will do this year needs to be done on GRAPH PAPER or the computer (if your teacher lets you) You should always use PENCIL for graphing. NEVER use pen for a graph. If you do not use pencil or graph paper, your graph will not be accepted. If you need graph paper and you have none at home, visit the following web site: Or search on google images for “graph paper”