The histogram, a special form of the bar graph, is used to depict frequency distributions of statistical data. Variables are represented by the x-axis of the histogram while the y-axis represents the frequency. The frequency of a measured value is represented by a bar-shaped area above the measured value – either relatively (in percent) or absolute.
Preferably, a histogram depicts variables representing classes of equal size, meaning that, for example, income would be represented in consistent Dollar ranges.
Please note that the definitions in our statistics encyclopedia are simplified explanations of terms. Our goal is to make the definitions accessible for a broad audience; thus it is possible that some definitions do not adhere entirely to scientific standards.