This paper investigates the use of peer- and self-assessment, through the platform Peergrade, in in-service teacher training: a field where these are little explored. The aims of the study are to examine the assessment skills of the teachers under an instructional approach proposed in the training courses and the validity of peer- and self-assessment in this field. The study analyzes the level of agreement between teachers’ peer- and self-assessment, and trainer’s assessments of the lesson plans produced by teachers (from Primary to High school). The results show substantial and almost perfect levels of agreement between the teachers’ peer- and self-assessments, and those of their trainers. These findings highlight that teachers show good assessment skills for the proposed approach, that peer- and self-assessment are also valid in the field of in-service teacher training, and the possibility of adopting these procedures as an indicator of the effectiveness of training courses.
