“…Although the definitions of an open classroom differs slightly across studies, the usual core elements include the possibility to engage in respectful debates and to express opinions on public issues. Previous studies have shown the positive relation of open classroom climate not only to students' political self-efficacy (Godfrey & Grayman, 2014;Manganelli et al, 2015;Perliger, Canetti-Nisim, & Pedahzur, 2006) and confidence in school participation (Godfrey & Grayman, 2014;Torney-Purta, Barber, & Richardson, 2004), but also to other related constructs, such as political trust (Claes, Hooghe, & Marien, 2012;Dassonneville, Quintelier, Hooghe, & Claes, 2012), political knowledge (Campbell, 2008;Hoskins, Janmaat, & Villalba, 2012), or pro-participatory attitudes and actual political participation (Campbell, 2008;Hooghe & Dassonneville, 2013;Hoskins et al, 2012;Manganelli et al, 2015;Perliger et al, 2006;Quintelier & Hooghe, 2013).…”