Assessing the Efficacy of Tier 2 Mathematics Intervention for Spanish Primary School Students.

• Tier 2 intervention in math might improve students' at-risk performance. • First to third-grade at-risk students might benefit from number sense based math intervention. • Children at risk in math might benefit from an explicit and systematic intervention. • Teachers are able to implement intervention programs with a high level of fidelity. • Interventionist teachers increase the generability of intervention studies results. This study explored the efficacy of a Tier 2 intervention within the context of the Response to Intervention (RtI) model implemented by Spanish first- to third-grade primary school teachers to improve at-risk students' early math skills. Teachers were instructed in the administration of a math curriculum-based measure composed of 5 isolated measures (quantity discrimination, missing number, single-digit computation, multidigit computation, and place value) to identify at-risk students and to monitor their progress; and in the implementation of a systematic and explicit instructional program to improve basic math skills in at-risk students. Implementation fidelity was analyzed using direct observations and self-reports. The intervention was conducted with adequate fidelity and had a significant positive impact on all grades. Significant differences were found between experimental and control students at risk of math failure in the improvement rate of quantity discrimination, missing number, and place value in all grades. Experimental at-risk students showed a monthly improvement, assessed using a combination of screening and progress monitoring measures. In conclusion, Spanish first to third graders at risk of math failure benefited from a Tier 2 intervention based on basic math skills, implemented by in-service teachers. [ABSTRACT FROM AUTHOR]