AN INVESTIGATION WAS CONDUCTED (1) TO DEVISE A NUMBER OF LABORATORY MEASURES OF INDIVIDUAL DIFFERENCES IN SUSCEPTIBILITY TO INTERFERENCE EFFECTS IN LEARNING AND (2) TO DETERMINE THEIR DIMENSIONALITY IN A VARIETY OF INTERFERENCE EFFECTS. SUBJECTS WERE 530 STUDENTS IN INTRODUCTORY COURSES IN EDUCATIONAL PSYCHOLOGY AT THE UNIVERSITY OF CALIFORNIA, BERKELEY. TWO TYPES OF EXPERIMENTAL LEARNING TASKS WERE USED--(1) SHORT-TERM MEMORY (STM) AND (2) SERIAL LEARNING. THE STM INCLUDED (1) IMMEDIATE DIGIT SPAN, (3) IMMEDIATE AND DELAYED COLOR-FORM MEMORY SPAN, (5) PROACTIVE INHIBITION OF DIGIT SPAN, (6) FORWARD AND BACKWARD DIGIT SPAN, PRE- AND POST-CUED, AND (7) REPEATED DIGIT SPAN. THE SERIAL TASKS INVOLVED (1) RETROACTIVE INHIBITION OF SERIAL LEARNING AND (2) DIFFERENT AMOUNTS OF INTRALIST INTERFERENCE. AGE, INTELLIGENCE (AS MEASURED BY "RAVEN'S PROGRESSIVE MATRICES"), COLLEGE GRADE-POINT AVERAGE, AND TWO PERSONALITY MEASURES WERE INCLUDED AS VARIABLES. COLLEGE GRADE-POINT AVERAGE WAS MOST HIGHLY CORRELATED WITH THE FACTOR OF RESISTANCE TO RESPONSE COMPETITION. (JK)