THIS STUDY AIMED AT--(1) CHARACTERIZING PROBLEM-SOLVING PROCESSES OF DIFFERENT INDIVIDUALS AND (2) DETERMINING THE EFFECTS OF TRAINING ON THE SUBJECTS' APPROACHES TO THEIR PROBLEM-SOLVING PERFORMANCE. THE DESIGN INCLUDED 50 NINTH-GRADE STUDENTS AND 50 COLLEGE FRESHMEN DIVIDED INTO EXPERIMENTAL AND CONTROL GROUPS IN WHICH SUBJECTS WERE MATCHED ON THE BASES OF AGE, IQ, AND EDUCATIONAL LEVEL. A PREVIOUSLY DEVELOPED PROBLEM WAS ADMINISTERED TO ALL SUBJECTS. EACH SUBJECT ATTENDED INDIVIDUAL TRAINING SESSIONS EVERY WEEK OVER A 6-MONTH PERIOD FOR A TOTAL OF 20 TO 24 SESSIONS. ANOTHER PREVIOUSLY DEVELOPED PROBLEM WAS ADMINISTERED AFTER TRAINING. STATISTICAL COMPARISONS WERE APPLIED TO THE PERFORMANCE OF THE EXPERIMENTAL AND CONTROL SUBJECTS AT BOTH EDUCATIONAL LEVELS. ACADEMIC GRADES WERE ALSO COMPARED. EVIDENCE SEEMED TO INDICATE THAT TACTICS AND NUMBER OF QUESTIONS ASKED ARE NOT CLEARLY RELATED TO NUMBER OF CORRECT SOLUTIONS TO THE PROBLEMS ADMINISTERED. ALSO, COLLEGE STUDENTS ASKED FEWER IRRELEVANT QUESTIONS THAN HIGH SCHOOL STUDENTS, AND EXPERIMENTAL SUBJECTS DID THE SAME WHEN COMPARED TO CONTROL SUBJECTS. THIS OCCURRENCE WAS ATTRIBUTED TO THEIR INCREASED EXPERIENCE AND KNOWLEDGE. FINALLY, COLLEGE STUDENTS ARE, ON THE WHOLE, BETTER THAN HIGH SCHOOL STUDENTS IN SOLVING PROBLEMS. (HB)