class interval

In statistics, the range of each class of data, used when arranging large amounts of raw data into grouped data. To obtain an idea of the distribution, the data are broken down into convenient classes (commonly 6–16), which must be mutually exclusive and are usually equal in width to enable histograms to be drawn. The class boundaries should clearly define the range of each class. When dealing with discrete data, suitable intervals would be, for example, 0–2, 3–5, 6–8, and so on. When dealing with continuous data, suitable intervals might be 170 ≤ X < 180, 180 ≤ X < 190, 190 ≤ X < 200, and so on.