A possible caveat when talking about innovative teaching approaches is that they are always innovative relative to a,mostly implied, “regular” practice, and this regular practice can vary across time and space. Context-based teaching, for instance, has become more or less mainstream in many countries nowadays, but not in others. To be included in our analyses,studies had to have a complete comparative design, so the teaching intervention is well-defined as the difference between the intervention and the control conditions. However, when synthesizing across studies, the definition of “regular” teaching might differ across studies and, given a lack of information and a limited number of studies, there is noway to control for that. This implies that our analysis has to rely on a linear additive effects model, ignoring the fact that innovations might work out differently for different regular teaching practices