In statistics, the quartile coefficient of dispersion is a descriptive statistic which measures dispersion and which is used to make comparisons within and between data sets.
The statistic is easily computed using the first (Q1) and third (Q3) quartiles for each data set. The quartile coefficient of dispersion is
Consider the following two data sets:
- Data set A: 2, 4, 6, 8, 10, 12, 14.
-
- n = 7, range = 12, mean = 8, median = 8, Q1 = 4, Q3 = 12
-
- coefficient of dispersion = 0.5
- Data set B: 1.8, 2, 2.1, 2.4, 2.6, 2.9, 3
-
- n = 7, range = 1.2, mean = 2.4, median = 2.4, Q1 = 2, Q3 = 2.9
-
- coefficient of dispersion = 0.18
The quartile coefficient of dispersion of data set A is 2.7 times as great (0.5 / 0.18) as that of data set B.
| This statistics-related article is a stub. You can help Wikipedia by expanding it. |
Famous quotes containing the word dispersion:
“The slogan offers a counterweight to the general dispersion of thought by holding it fast to a single, utterly succinct and unforgettable expression, one which usually inspires men to immediate action. It abolishes reflection: the slogan does not argue, it asserts and commands.”
—Johan Huizinga (1872–1945)