ABSTRACT
The 80/20 rule, known as the Pareto principle, asserts that approximately 80 percent of the effects in large systems are caused by 20 percent of the variables in that system. The person who first recognized the ubiquity of the 80/20 distribution, the Italian economist Vilfredo Pareto, observed that 80 percent of the land in Italy was owned by 20 percent of the population. After some additional analysis, he realized this distribution described not only wealth in Italy, but in all countries—and astonishingly, in large, complex systems generally, including those in economics, management, quality control, and education, to name a few. Focusing instruction on a Pareto subset of a comprehensive curriculum runs contrary to coverage-driven approaches found in many schools, but it will yield superior outcomes with less effort than exhaustive approaches. 80/20 analysis has been used to identify the critical 20 percent of errors made by writing students.
