The research conducted in the multidisciplinary Lingot project concerns the development of Computer-Based Learning Environments (C.B.L.E.) to help teachers take into account the diversity of students' cognitive profiles. It aims to provide teachers with tools to manage the heterogeneity of learning needs in elementary algebra for students at the end of compulsory schooling. First, we show how the Lingot project draws on cognitive and anthropological approaches. Second, we outline how didactical models of diagnostic assessment have been developed in the Lingot project through the use of automated computer processes. Finally, we present some of the elements of learning routes adapted to the diagnosis and management of interactions differentiated according to pupils' responses. Key words: diagnostic assessment, modeling of students' knowledge, differentiated learning routes, teaching and learning of elementary algebra, cognitive and anthropological approaches. DIAGNÓSTICO Y RUTAS DE APRENDIZAJE EN ÁLGEBRA ELEMENTAL Resumen-Los trabajos de investigación realizados en el marco del proyecto multiplisciplinario Lingot, pretenden la concepción de Ambientes Informáticos para el Aprendizaje Humano (A.I.A.H.) con el objetivo de facilitar la consideración por parte de los profesores, de la diversidad cognitiva de los alumnos. Se trata de otorgar a los profesores, herramientas para manejar la heterogeneidad de los aprendizajes en álgebra elemental al final de la escolaridad obligatoria.