Karoline Afamasaga-Fuata’iThis paper presents a case study of a student who developed quadratic schemes by solving a contextual problem during a teaching experiment. Mary reflectively abstracted patterns from graphical transformations, critical points, rates of change and equations representing variations of a base context whilst interacting and negotiating meanings with the researcher. A multi-representational software assisted Mary in verifying/justifying her conjectures. Findings include Mary’s schemes to characterize quadratic covariations. The student-researcher interactions fostered the development and consolidation of Mary’s quadratics conceptions.