Julie, CyrilMbekwa, MondeSimon, Marius2018-05-242018-05-242016Julie, C. et al. (2016). The effect size of an intervention focusing on the use of previous national senior certificate mathematics examination papers. Journal of Educational Studies, 15(1): 1 – 221680-7456http://hdl.handle.net/10520/EJC199584http://hdl.handle.net/10566/3731This study reports on an intervention that emanated from a concern a mathematics teacher had about the unsatisfactory performance of grade 12 learners in the school-based mid-year examination. The intervention was based on distributed practice and the effect size of the intervention was determined as an indicator of the effectiveness of the intervention. Different effect sizes are reported and the reasons for their acceptance or non-acceptance are presented. Overall the results indicate that if all the different effect sizes are taken into account, the intervention had a medium to high effect. Given that the intervention was driven by aspects of teaching and was done at school, it is recommended that more attention be accorded to those aspects of teaching that enhance achievement in Mathematics.enThis is the author-version of the article published online at: http://hdl.handle.net/10520/EJC199584Distributed practiceEffect sizeNational Senior Certificate Mathematics examinationAchievement in MathematicsLow-performing schoolsArticle