A national survey examined the factors that are primarily responsible in determining an individual's overall quality of life. Using the critical incident technique, researchers surveyed a representative sample of 50- and 70-year-old adults in the United States in order to determine which of 15 factors they felt had negative and positive effects on their quality of life. Considered in the survey were the following factors: spouse, children, friends, work, health, socializing, active recreation, relatives, material well-being, passive recreation, helping, understanding oneself, learning, creativity, and government. The respondents were asked to identify the three areas that had the most positive effects on their lives at age 30, age 50, and at present. Over the life span, "spouse" is the most frequent single dominant positive factor. Men considered work and children the second and third most positive influences on their quality of life, whereas women considered children and then work the second and third most positive factors in their quality of life. Both men and women identified material well-being as the single dominant negative factor determining quality of life. Both sexes mentioned learning, health, and spouse as important negative factors. (MN)