Repeated formative, diagnostic assessment lies at the heart of student-centred learning, providing students with a continuous stream of information on the mastery of different topics and making suggestions to optimize the choice of subsequent learning activities. When integrated into a system of e-learning, formative assessment can make that steering information instantaneous, which is a crucial aspect for feedback in student-centred learning. This empirical study of the role of formative assessment in mathematics e-learning focuses on the important merit of integrating these assessments into a system of state or national testing. Such tests provide individual students with crucial feedback for their personal learning, teachers with information for instructional planning, and curriculum designers with information on the strengths and weaknesses in the mastery states of students in the program and the need to accommodate any shortcomings. Lastly, they provide information on the quality of education at state or national level and a means to monitor its development over time. We shall provide examples of these merits based on data from the national project ONBETWIST, part of the Dutch e-learning program Testing and Test-Driven Learning. ; La repetida evaluación diagnóstica y formativa es uno de los elementos clave del aprendizaje centrado en el alumno, ya que ofrece a los estudiantes un flujo continuo de información sobre su nivel de conocimientos en distintas materias y permite optimizar la posterior elección de actividades de aprendizaje. Cuando se integra en un sistema de aprendizaje virtual, la evaluación formativa puede convertir esta información en instantánea, lo que constituye un aspecto crucial para el retorno de información en un aprendizaje centrado en el alumno. Este estudio empírico sobre el papel de la evaluación formativa en el aprendizaje virtual de matemáticas se centra en la ventaja de integrar estas evaluaciones en un sistema nacional o estatal de exámenes. Estos exámenes proporcionan a los ...