AN EXPERIMENT WAS CONDUCTED TO DETERMINE THE FUNCTIONAL RELATIONSHIPS BETWEEN SUCH VARIABLES AS TYPE OF MATERIAL, NUMBER OF RELEVANT ATTRIBUTES, AND PERFORMANCE OF A PERSON ATTAINING CONCEPTS. CONCEPT ATTAINMENT BOARDS OF THE BRUNER (1956) TYPE WERE USED, AND VARIOUS PARAMETERS CONTAINED IN THE BOARDS WERE MANIPULATED. THE NUMBER OF RELEVANT AND IRRELEVANT ATTRIBUTES IN A CONCEPT WAS VARIED. INSTRUCTION, THE TYPE OF PROBLEM, PROBLEM ORDER, AND THE TYPE OF BOARD (FIGURAL OR VERBAL) WERE ALSO TREATED AS VARIABLES. INSTRUCTIONS FOR THE TASK WERE EITHER GIVEN TO THE 64 FEMALE AND 48 MALE SUBJECTS BY A TAPE RECORDING OR FROM A BOOKLET. FOUR DISTINCT SEQUENCES OF CONCEPTS WERE DEVELOPED AND EACH SEQUENCE WAS USED WITH SIX MALES AND EIGHT FEMALES. THE DEPENDENT VARIABLES WERE TIME-TO-CRITERION AND NUMBER OF CARD CHOICES. RESULTS FROM THE VERBAL CONCEPTS SHOWED THAT SEX, INSTRUCTIONS, AND CONCEPT ORDER HAD NO SIGNIFICANT EFFECT. THE J-2 CONCEPTS (COMBINATIONS OF TWO) WERE EASIER THAN THE J-3, (COMBINATIONS OF THREE) AND RECEPTION CONCEPTS WERE EASIER THAN SELECTION CONCEPTS. ON THE TWO TRAINING CONCEPTS, THE J-3 CONCEPT WAS EASIER THAN THE J-2 BOTH IN TERMS OF TIME AND NUMBER OF CARD CHOICES. IT WAS HYPOTHESIZED THAT UNUSUAL RESULTS OBTAINED FROM THE FIGURAL BOARD CONCEPT WERE DUE TO THE SALIENCE LEVELS OF THE ATTRIBUTES. IT WAS FURTHER HYPOTHESIZED THAT ANY ANALYSIS OF CONCEPT MUST CONSIDER NUMBER OF RELEVANT AND IRRELEVANT ATTRIBUTES AND THE SALIENCE LEVEL. (JC)