This paper presents findings of a study that examined the role of social networks in promoting or inhibiting student achievement. The study was based on the convoy model--a "convoy" is a dynamic, hierarchical structure of social relations that provide the individual with a supportive base from which to develop personal competencies. The premise of the study was that academic achievement would be related positively to the amount of social support provided by social-network members (if those persons providing support also held positive attitudes toward school achievement). Data were obtained through: (1) interviews with 63 children in grades 2 and 5 at a Dade County (Florida) public elementary school; (2) parent questionnaires; (3) a survey of students identified by the 63 children as their friends; and (4) analysis of student grade-point averages (GPAs) and Stanford Achievement Test (SAT) scores. Findings suggest that the support provided by social network members does not promote achievement directly, but interacts with the attitudes of the support providers. The findings help to explain why social support is not always related positively to achievement outcomes and why social-network member attitudes will not necessarily predict achievement. A combination of strong support and positive attitudes from social-network members are most likely to foster school achievement. Four figures are included. (contains 26 references.) (LMI)