Researchers have recently used traditional item response theory (IRT) models to measure mathematical knowledge for teaching (MKT). Some studies (e.g., Hill, 2007; Izsak, Orrill, Cohen, & Brown, 2010), however, have reported subgroups when measuring middle-grades teachers' MKT, and such groups violate a key assumption of IRT models. This study…

Despite the current legislation requiring sex education as part of the school curriculum in Portugal, great obstacles to its implementation remain. Furthermore, sex education is far from being systematically administered. Thus, the main interest in our project was to validate a scale that measures teachers' attitudes towards sex education. There…