Traditionally, rubrics have been used in a summative way as a tool to grade students’ work, but without the giving the chance to students to have access to that rubric. (Andrade & Valtcheva, 2009; Jonsson & Svingby, 2007). In the past few years, rubrics have gained popularity and used from a formative perspective (Dawson, 2017; Rekalde Rodríguez & Buján Vidales, 2014). It is necessary the use of rubrics within a formative context to generate positive effects on students’ performance and their self-regulated learning skills (Panadero & Jonsson, 2013). This formative process is associated with the provision of feedback, give the opportunity to resubmit assignments, peer-assessment and self-assessment (Black & Wiliam, 1998). An important aspect is how accurate students are in relation to self-assessment or peer-assessment. It is also a key factor about the quality of the teaching-learning process. In other words, the competence to identify correctly right and wrongs, in comparison with the judgement of the teacher is socially accepted in relation to accuracy (Topping, 2003). The aim of this study is to explore accuracy when students self- and peer assessed. Students performed two similar tasks with the same rubric provided by the teacher within a course of the third year of the degree in Sports Sciences in Spain. Regarding the results, which will be presented in the conference, we expect an improvement in accuracy in the second task due to students’ expertise, content learning and the calibration after assessing the first assignment (Dochy, Segers, & Sluijsmans, 1999). In conclusion, we could assess the teaching-learning process itself performed along the course in relation to accuracy in students’ self- and peer-assessments.