Grades are almost completely relative, in effect ranking students relative to others in their class. Thus extra achievement by one student not only raises his position, but in effect lowers the position of others.

Children from a given family background, when put in schools of different social compositions, will achieve at quite different levels.

The results indicate that heterogeneity of race and heterogeneity of family educational background can increase the achievement of children from weak educational backgrounds with no adverse effect on children from strong educational backgrounds.

Schools are successful only insofar as they reduce the dependence of a child's opportunities upon his social origins.

The higher the social class of other students the higher any given student's achievement.

As an example, one of the schools I have been studying is too small to compete effectively in most sports, but participates with vigor each year in the state music contests.

Grades are almost completely relative, in effect ranking students relative to others in their class. Thus extra achievement by one student not only raises his position, but in effect lowers the position of others.