A histogram groups numbers in a data set into ranges.
The data used in a histogram is continuous data. Continuous data is measured whereas discrete
data, which is used in bar charts, is counted.
For example, a histogram can show the pattern of P1 incidents logged over a four-week period
after a product release. For the first week after the product was released, P1 incidents are low
because users do not really understand the product enough to use it. In the second week, more
users start working with the product and P1 issues increased. In the third week, P1 issues
increase even more as more users began working with the product. In the fourth week, P1 issues
stay the same as the third week. The information suggests that it is not necessary to increase
support staff until the third week after a product is released.