Recent studies conducted in Europe using communicative methodology highlight that different ways of grouping students has a direct effect on their academic output. This article analyzes how said research methodology identifies and analyzes those student groupings that provide greater academic success and improve classroom coexistence at Spanish educational centers. Said methodology entails all of the research participants researchers, teachers, families, and students reflecting on the consequences of streaming, mixture, and inclusion for student academic achievement. Following this, our conclusions are compared with the policies and educational practices implemented in Spanish schools, which are not based on scientific knowledge and do not usually lead to academic success. Finally, recommendations are presented for future educational policies with the aim of providing an alternative for teachers and educational managers that would substantially improve student academic success.