Reported are the results of a study designed to determine the most efficient learning sequence appropriate for preschoolers in learning three set relations. The efficiency of a particular ordering of the relations, equivalence (E), greater than (G), less than (L)) was evaluated in terms of time required to reach criterion, and amount of transfer. The permutations of three relations required six treatment groups, while two control groups were used. One dependent variable was the child's ability to identify a set with a particular relation to a given set. The other dependent variable was the time required for the treatment group to reach criterion performance. The children studied were four years old. It was found that these children could understand and successfully apply these set relations. The most efficient learning sequence was in the order E, G, L. (Author/RS)