The most common designs in intervention research, which focuses on improving learning outcomes, are controlled designs – either randomized controlled trials or quasi-experimental designs (Wang et al., 2016). In controlled designs, children’s mathematical skills are measured before and after the intervention phase, and their performance is compared to control groups either receiving another type of intervention (i.e. active control group) or not receiving any intervention (i.e. passive control group). The figure illustrates an example of an intervention design with three measurement points.
- Wang, A. H., Firmender, J. M., Power, J. R., & Byrnes, J. P. (2016): Understanding the program effectiveness of early mathematics interventions for prekindergarten and kindergarten environments: A meta-analytic review, Early Education and Development. doi:10.1080/10409289.2016.1116343