Diagnostic Analysis of the Mathematics Lessons Considering the Influence of Teaching Style and Lesson Plan Adherence in the New Textbooks Implementation in El Salvador

The performance of students' mathematic skills in El Salvador is likely to have improved since the recent intervention of textbooks in 2018. Few previous studies have addressed this intervention in El Salvador, but researches at classroom level have not been carried out yet. The present article attempts to determine whether or not a difference exists in the students' learning achievements between a class carried out with the textbook and workbook, and a class carried out without them by using a controlled trial pre and post test. Furthermore, it presumes to understand the teaching style that might explain the difference between both groups by using video recording analysis. The findings rise the importance of the lesson plan adherence and teaching style, since the non-material-based lessons showed a better learning achievement level than the material-based lessons.