AN ATTEMPT WAS MADE TO ASSESS THE EFFECTS ON ADULT LEARNING OF DIFFERENTIALLY STRUCTURED INTRODUCTORY COGNITIVE LEARNING TASKS AND MATERIALS, AND THE INTERACTION OF INTELLIGENCE WITH THE EXPERIMENTALLY MANIPULATED MATERIAL AND TASK CATEGORIES. ABOUT 96 ADULTS WHO WERE UNFAMILIAR WITH THE CONCEPT OF NUMBER BASES WERE CLASSIFIED ACCORDING TO A 4X3X4 FACTORIAL DESIGN. DURING INDIVIDUAL SESSIONS, THE LEARNER, CLASSIFIED BY INTELLIGENCE LEVEL, WAS GIVEN A PROGRAMED BOOKLET ON ONE OF FOUR STRUCTURAL LEARNING MATERIALS RANDOMLY ASSIGNED. UPON COMPLETION, THE LEARNER WAS GIVEN A LEARNING TASK, BY TEACHING MACHINE, UNDER AN EXPERIMENTAL CONDITION CONSISTING OF THREE DIFFERENTIALLY SEQUENCED SETS OF PAIRED ASSOCIATES, CORRESPONDING TO NUMBERS IN THE BASE FOUR NUMBER SYSTEM. THE NUMBER OF TRAILS REQUIRED, TOTAL ERRORS, AND POSTTEST SCORES SERVED AS MEASURES OF THE EFFECTIVENESS OF THE EXPERIMENTAL CONDITIONS. INTELLIGENCE WAS POSITIVELY RELATED TO TASK PERFORMANCE, COMPLETE TASK SEQUENCING LED TO MORE RAPID LEARNING THAN DID PARTIAL SEQUENCING, INTRODUCTORY MATERIALS WERE ESPECIALLY USEFUL WITH THE MORE INTELLIGENT ADULTS, COMPLETELY SEQUENCED LEARNING TASKS WERE EVIDENTLY MOST BENEFICIAL WITH THE LESS INTELLIGENT ADULTS, AND MEN CONSISTENTLY OUTPERFORMED WOMEN, PARTICULARLY IN APPLYING NUMBER BASE PRINCIPLES. (LY)