Stem-and-leaf display
A
stem-and-leaf display is a device for presenting quantitative data in a graphical format, similar to a histogram, to assist in visualizing the shape of a distribution. They evolved from Arthur Bowley's work in the early 1900s, and are useful tools in exploratory data analysis. Stemplots became more commonly used in the 1980s after the publication of John Tukey's book on
exploratory data analysis in 1977. The popularity during those years is attributable to their use of monospaced typestyles that allowed computer technology of the time to easily produce the graphics. Modern computers' superior graphic capabilities have meant these techniques are less often used. A
stem-and-leaf display is often called a
stemplot, but the latter term often refers to another chart type. A simple stem plot may refer to plotting a matrix of
y values onto a common
x axis, and identifying the common
x value with a vertical line, and the individual
y values with symbols on the line.