Wikipedia:
An achievement gap refers to the observed disparity on a number of educational measures between the performance of groups of students, especially groups defined by gender, race/ethnicity, ability, and socioeconomic status. The achievement gap can be observed on a variety of measures, including standardized test scores, grade point average, dropout rates, and college-enrollment and -completion rates. While most of the data presented in this article comes from the United States, similar or different gaps exist for these, and other groups in other nations.
http://en.wikipedia.org/wiki/Achievement_gap
Me:
An achievement gap is represented by the contrast between who we are capable of being as individuals, community members and citizens of this planet, and the lives and world we have created. It is apparent when comparing the soundness of our planet and its inhabitants 100 years ago to its its health today. It is inherent in the disparity between the quality of life of the rich and everyone else. And I see it every day in the mirror when I compare how my ass looked at 30 and how it looks like now.
Achievement Gap!