[ES] Este trabajo analiza la significatividad de la aplicaci?n del modelo de Van Hiele en Geometr?a de 1? de ESO. Por una parte, se aplic? un cuestionario v?lido y fiable a 137 alumnos antes y despu?s de estudiar la asignatura, determinando los errores al inicio del curso y los persistentes tras el estudio y constatando la inexistencia de diferencias significativas en el aprendizaje por raz?n de g?nero. Por otra parte, se realiz? un estudio cuasi-experimental del aprendizaje en dos grupos de 18 y 21 alumnos de la muestra anterior. Uno de estos grupos se seleccion? como grupo experimental y utiliz? las unidades did?cticas elaboradas para la investigaci?n, basadas en el modelo de Van Hiele. El grupo de contraste sigui? la metodolog?a tradicional. Se encontraron diferencias significativas favorables al grupo experimental y se analiz? en detalle la correcci?n de los errores.

[EN] This paper analyzes the significance of applying the Van Hiele model in Geometry of the first course in ESO students. On one hand, a valid and reliable questionnaire was applied to a sample of 137 students before and after studying the subject. The students? errors before and after the geometry course were determined. It was found that there aren?t significant differences in gender learning. Furthermore, a quasiexperimental research about learning in two groups of 18 and 21 students from the previous sample was conducted. One of these two groups was selected as experimental group and used the teaching units for research, based on Van Hiele model. The other one was a contrast group and followed the traditional methodology. The results showed significant differences for the experimental group, and the correction of the errors was widely analyzed.