five-number summary
in exploratory data analysis, the characterization of a data set through the use of five summary statistics: the two extreme scores, the upper and lower quartiles, and the median or middle quartile. For example, suppose the scores on a test are 100, 93, 90, 82, 76, 72, 64, 61, 60, and 47. The five-number summary from highest to lowest numbers would be 100, 90, 74, 61, and 47—that is, 100 is the highest extreme score, 90 is the highest quartile (the midpoint in the top half of the data), 74 is the middle point, 61 is the lowest quartile (the midpoint in the bottom half of the data), and 47 is the lowest extreme score. These values provide the basic highlights of a set of data and can be used to create a box-and-whisker plot.