The shortage of teachers and the appreciation of the quality of teaching across Europe has intensified the shortening of training time, the introduction of school-based training and the recruitment of professionals from other careers (William & Forgasz, 2009). In the domestic context, these changes have only intensified in the last year or two, with the number of second carrier teachers (SCT) increasing sharply in the last year. In the domestic context, the field is still unexplored.  A better understanding of the specificities of SCT in the country will help to develop a more effective training development tool. 

In the context of teachers' professional development, the role of trainers is coming to the fore, supporting their professional development and their becoming a community (Dengerink et al., 2015). This is also against the background of a European-wide phenomenon of trying to compensate for the shortage of teachers by providing accelerated, short and school-based training, and increasingly identifying teachers working in schools as trainers. This creates a new expectation for school-based teacher educators, as they have to interpret their roles and (re)position themselves in the continuum of constant boundary crossing (at the school-university boundary), which also implies identity transformation work, in a sense they also 'become experts to novices' (Kaasila et al, 2023). The focus of our research is on how partner school teachers' identities are shaped during their entry and participation in teacher education.