2.2 Summary: Characteristics of a Good Graph

Here is a summary of the characteristics of a good graph.

• It is plotted on a grid (graph paper) or digitally, depending on what the teacher has asked for.

• The axes are highlighted (darker than the rest of the grid lines) and are drawn with a ruler.

• Both axes are labelled with the variable name and its units. Note that we do not label them x or y!

• The independent variable is plotted on the horizontal (x) axis.

• The dependent variable is plotted on the vertical (y) axis.

• The data points have point protectors

• A line of best fit is drawn which shows the trend of the data. The line of best fit may have some points above it, some below it, and some on it. If the trend of the data is linear, the line of best fit is drawn with a ruler. If the trend of the data is curved, a smooth curve should be drawn.

• The graph is clearly titled using the convention dependent variable vs. independent variable.

• The axes are properly scaled so that the graph fits the space, the grids are consistently scaled, and all of the data fits on the graph.

• The slope calculation points are clearly marked with a (+) on the line of best fit