In support of the premise that a better understanding of the causes of poor student motivation may lead to the development of techniques to stop unmotivated students from dropping out of college, this paper reviews the literature on the nature of motivation among adolescents and factors influencing academic achievement. After introductory comments on the problem of underprepared and unmotivated community college students, the paper considers the following aspects of student motivation: (1) the educational attitudes and low level of involvement in learning of unmotivated students; (2) the incidence and causes of dropping out; and (3) the special motivational problems of underprepared students. Arguing that most unmotivated community college students experienced similar problems in high school, the paper then considers their attributes in terms of college entrance examination scores, knowledge level, courses, family characteristics, lack of involvement and motivation, and tendency to drop out of school. The next section reviews materials on motivation in adolescents, considering social influences, adolescent identity, locus of control, attributions for success or failure, academic goals, aspirations, deferred gratification, and academic self-concept. After reviewing students' reasons for attending college, the paper considers ways in which the high school environment and curriculum can be modified to enhance motivation; reviews research on single-sex high schools and boarding schools; and looks at ways the community environment and students' parents can influence motivation. Next, ways of increasing students' involvement in learning and raising their expectations are discussed. After suggesting that more attention be paid to the motivation of average students, the paper highlights teaching methods that can help motivate all students. A 58-item bibliography is included. (EJV)