“…The established stage-order overlaps with those reported in research into teacher development (Berliner, 2004;Fuller, 1969;Huberman, 1993) and provides a means to link the teacher's performance score back to specific teaching practices associated with that stage of development. It has been shown that using these stage models to scaffold feedback and coaching has medium to large effects on development of teaching quality (Tas, Houtveen, Van de Grift, & Willemsen, 2018) and may outperform feedback and coaching methods not based on the stages (Antoniou & Kyriakides, 2011). Furthermore, both student surveys and classroom observations have been proven valid measures to identify teachers' stage of development (Maulana & Helms-Lorenz, 2016;Van de Grift et al, 2014;Van der Lans et al, 2015, 2017, 2018).…”