“…A large body of research has supported the validity of the STRS. Its three-factor structure has been confirmed in several studies, both within the US (Pianta, 2001) and in other countries (Fraire, Longobardi, Prino, Sclavo, & Settanni, 2013;Koomen et al, 2012;Solheim, Berg-Nielsen, & Wichstrøm, 2012;Tsigilis, Gregoriadis, Grammatikopoulos, & Zachopoulou, 2018;Zhang, 2010). Moreover, teacher perspectives on relationship quality, assessed by the STRS, have been found to converge with teacher reports in narrative measures (Koenen, Vervoort, Verschueren, & Spilt, 2018;Spilt & Koomen, 2009), peer reports (Doumen et al, 2009;Zee, de Bree, Hakvoort, & Koomen, 2020), student reports (Chen, Zee, Koomen, & Roorda, 2019;Doumen et al, 2009;Henricsson & Rydell, 2004;Koomen & Jellesma, 2015;Vervoort, Doumen, & Verschueren, 2015;Zee & Koomen, 2017), and observer ratings of dyadic teacher-student interactions (Doumen, Koomen, Buyse, Wouters, & Verschueren, 2012;Henricsson & Rydell, 2004).…”