“…By investigating the relationship between principal leadership, collective efficacy, and teacher collaboration in Germany, the study builds on existing research into how cultural differences affect collective efficacy in school contexts (Klassen et al, 2010). Our finding of strong relationships between principal leadership and the collective efficacy of teachers confirms results from other countries such as Israel (Qadach et al, 2019), Iran (Hallinger et al, 2018), Serbia (Ninković and Knežević-Florić, 2018), China (e.g., Liu et al, 2019), and the United States (e.g., Voelkel, 2019).…”