Although most students experience relative success at school, there remains a population of educationally marginalised learners within educational settings, indicating that mainstream schools are challenged to appropriately meet the diverse needs of every student. Designed to support students on the cusp of school disengagement, alternative education provision presents a conduit between educationally marginalised learners and educational opportunities. Constructed from a social psychological perspective, this study draws on an expectancy-value model of achievement to explore how antecedent educational experiences inform subsequent ability-, expectancy-, and value- beliefs. The naturalistic study involved three case studies across three alternative education provisions in South Australia: an alternative school, an alternative placement, and an alternative program. Findings identified the formation of beliefs to be socially constructed and influenced by previous achievement-related experiences and affective interactions. This study highlights the enduring influence of social interactions on educationally marginalised students' beliefs and acknowledges that alternative education provision can be both complex and contradictory.