The professional development of teachers has a definite impact on the improvement of the entire
educationalsystem (OECD, 2018; Darling-Hammond, 2017). Forthisreason, the main international
organizations - OECD (2013 ), European Commission (2012 ) - ask countries to establish
feedback and accountability procedures for in-service training (ITT), for the ‘
which teachers engage in further education or training to refresh or upgrade their professional
knowledge, skills and practices in the course of their employment’ (UNESCO, 2019). Researchers
state that here are numerous factors to be considered in carrying out this work: the type and quality
of training, school climate, students’ skills, knowledge domain, etc. (Lipowsky & Rzejak, 2015).
After a brief presentation of howthe mostrecentsystematic reviews on the topic have been conducted
(Filges et al, 2019; Egert et al, 2018; Kalinowski et al., 2019), this article presents the results of a study
on the terms and constructs in use in the context of the researches into in-service teacher/continuing
professional training, impact/effect, and programs/instructions. The data and information collected
offer a comparative analysis (Esser & Hanitzsch, 2012), based on systematic reviews (Polanin et al.,
2019) and a meta-analysis, useful for setting up further meta-analytical investigations on the topic
especially in terms of the disambiguation of terms and the narrowing of the field.
The training of in-service teachers in many countries has been made compulsory and structural
and is conceived as an opportunity for growth and professional development for the entire school
community, and a strategic and functional logic forimproving the quality of the schoolsystem (Perla,
However, ministries of education do not yet have a univocal model and shared procedures
capable of describing and analysing the impact that the training provided has in the terms set out
in the European Commission (2020): output - results achieved immediately, i.e. increase in skillsfocus subject to training; outcome - wider benefits for involved teachers - improvement of teaching
practices of teachers involved in training; outreach - effects on the institutional and social context of
the school where and of the territory within which the teachers involved in the training.