ERROR BAR

'Error bars' are used on graphs in the experimental sciences, to indicate the range of one standard deviation on one experimental measurement. Error bars can be used to visually compare two quantities, to determine whether differences are statistically significant. They can also show how good a statistical fit the data has to a given function. Scientific papers in the experimental sciences are expected to include error bars on all graphs, though the practice differs somewhat between sciences, and each journal will have its own house style.