THE MAJOR FACTORS AFFECTING THE CHOICE OF SCIENCE AS A CAREER WERE EXAMINED FROM ELEMENTARY SCHOOL THROUGH 4 YEARS BEYOND COLLEGE. DIMENSIONS OF INDIVIDUAL PERSONALITY AND OF ENVIRONMENT WERE INCLUDED AS STUDY ELEMENTS. THE EMPHASIS ON THE OCCUPATIONAL CHOICE PROCESS NECESSITATED A CONCENTRATION ON PERSONALITY ASSESSMENT, INCLUDING THE SUBFACTOR OF ABILITY. DEPENDENT VARIABLES USED WERE EDUCATIONAL DECISIONS AND CAREER PLANS. A 5-YEAR OVERLAPPING LONGITUDINAL DESIGN WAS EMPLOYED TO INVESTIGATE IN ONLY 5 CALENDAR YEARS THE CRITICAL 16 YEARS OF THE DEVELOPMENT PROCESS OF BECOMING A SCIENTIST. THIS WAS ACCOMPLISHED BY SELECTING 700 MALE STUDENTS FROM 5 DIFFERENT GRADE LEVELS, 3 GRADES APART. AN OVERLAP OF 2 YEARS BETWEEN EACH GRADE WAS ALLOWED, TO COMPARE THE ADJACENT GROUPS. EACH STUDENT WAS CONTACTED THROUGH BOTH INTERVIEWS AND QUESTIONNAIRES DURING EACH STUDY YEAR TO DETERMINE CAREER PLANS AND EDUCATIONAL DECISIONS. CONTACT WAS MAINTAINED WITH OVER 90 PERCENT OF THE ORIGINAL SAMPLE. DATA ANALYSIS UTILIZED SUCH TECHNIQUES AS THE MULTIPLE GROUP DISCRIMINANT FUNCTION, MULTIPLE REGRESSION ANALYSIS, AND ANALYSIS OF VARIANCE AND COVARIANCE. MAJOR FACTORS DISCUSSED WERE ABILITY, FAMILY SOCIOECONOMIC STATUS, INTERESTS, AND INTROVERSION. THE REPORT CONCLUDED THAT THESE MAJOR FACTORS AFFECTING THE PROCESS OF CAREER DEVELOPMENT WERE KNOWN AND MEASURABLE. IMPLICATIONS FOR EDUCATIONAL PRACTICE AND FOR FURTHER RESEARCH WERE PROVIDED. (JH)