Graphs of various types provide convenient visual representations of scientific data that would otherwise be presented in intimidating blocks of text or a series of numbers. Graphs represent statistics such as changes over time, comparisons, or parts of a whole. Graphs can be used to make date more accessible to both scientists and laypersons.
Several types of graphs exist. A pie chart is used to compare the different ratios of parts to a whole. However, these are not often used in their default state because it is difficult to compare quantities based on a visual angle as opposed to the length of a bar.
Bar charts can compare two sets of data, such as the effectiveness of an experimental medicine versus a placebo. Bar charts are used to compare a single snapshot in time typically, but they can be used to denote different periods.
Line charts are mostly used to show a changing trend, such as animal migrations or populations in a given area. Because of the connectedness of the lines, this type of chart provides a greater sense of continuity and is best suited for tracking changes over time. Line graphs run along two axes. The horizontal axis is an independent variable such as time. The vertical axis represents a variable that depends on the data in the horizontal axis.