Study of retention of some topics of elementary nonmetric geometry

Retention was measured of the task "specifying sets, intersections of sets, and separations of sets, using points, lines, and curves," as well as of subordinate knowledges contributing to the learning of this task, in 5 groups each of 16 6th-grade students after an interval of 9 weeks. Experimental treatments during original learning represented variations in task examples and in time following practice of examples. The results show significantly lower retention for the group having the smallest variety in task examples, but no other differences. In addition, marked changes are shown between immediate and 9-week retention in patterns of retention of subordinate knowledges.