TO STUDY WHICH OF SEVERAL CONDITIONS PROMOTES EFFICIENT CONCEPT LEARNING, AN EXPERIMENT INVOLVING 2 CONDITIONS, METHOD OF PRESENTATION OF STIMULI AND RATIO OF POSITIVE TO NEGATIVE STIMULI, WAS ADMINISTERED TO 80 SECOND-GRADE CHILDREN. THE CHILDREN WERE DIVIDED INTO 8 TREATMENT GROUPS. THESE 8 GROUPS WERE FORMED BY VARYING THE 2 METHODS OF PRESENTATION, SIMULTANEOUS AND SUCCESSIVE, WITH THE 4 RATIOS OF POSITIVE TO NEGATIVE INSTANCES, P100 (POSITIVE INSTANCES ON ALL TRIALS), P75, P50, AND P25. AN INSTANCE WAS THE SHOWING OF A SPECIFIC GEOMETRIC SHAPE TO THE SUBJECT. IF THE SHAPE WAS A TRAPEZOID, THAT WAS THE POSITIVE INSTANCE. ANY OTHER SHAPE WAS A NEGATIVE INSTANCE. CHILDREN RECEIVED ACQUISITION, TRANSFER, AND RETENTION TASKS. THE SCORES ON THE ACQUISITION PHASE SHOWED THAT THE SUCCESSIVE METHOD OF PRESENTATION RESULTED IN SIGNIFICANTLY MORE CORRECT RESPONSES THAN THE SIMULTANEOUS METHOD. THERE WAS NO SIGNIFICANT DIFFERENCE BETWEEN THE 2 METHODS ON EITHER THE TRANSFER OR RETENTION TASKS. THE RATIO VARIABLE DEMONSTRATED A POSITIVE RELATIONSHIP WITH PERCENTAGE OF CORRECT RESPONSES ON THE ACQUISITION TASK. ON THIS TASK, THE P25 GROUP DID SIGNIFICANTLY WORSE THAN THE OTHER 3 GROUPS. ON THE ACQUISITION TASK, THE RATIO RANKING IN TERMS OF MOST CORRECT RESPONSES WAS (1) P100, (2) P75, (3) P50, AND (4) P25. ON THE TRANSFER AND RETENTION TASKS, THE RANKINGS WERE (1) P100, (2) P50, (3) P25, AND (4) P75. THIS DOCUMENT IS BASED ON A MASTER'S THESIS DONE AT THE UNIVERSITY OF WISCONSIN. (WD)