This research sought to identify if the increase in average proficiency of pupils in basic education in the State of Tocantins occurred between the years 2001 to 2007 could be explained by improved qualification of Mathematics and Portuguese teachers who participated in training activities promoted by the authors from 2003 to 2008. The relationship between teacher quality and cognitive performance of students are not easy to establish or measure, although in the current scenario of the research in the area of teacher effectiveness there is already considerable evidence that the teacher is the most important factor explaining the performance of school students. The Training Program  conducted over six years emphasized the acquisition of subject content, of skills focused on participatory instruction and work in cooperative groups with students, accompanied by periodic applications of formative assessments to monitor progress of students. The proposed change in teaching practice in the classroom was supported by the systematic distribution of instructional material consisting of books for teacher and booklets of exercises for students. With the aim to test if there were  positive effects of the training program on students performance a research was conducted with 538 teachers who were enrolled in the first stage of a lato sensu graduate program in School Evaluation in the areas of Mathematics and Portuguese. Variables defining participation and use of instructional material were derived from two questionnaires answered by the teachers. These variables were shown to be correlated to the mean performance of students at their schools in 2007 controlled by the mean performance in 2001. The results confirmed the hypothesis posed at the beginning that teacher training program can increase students' learning at the eighth grade at schools with teachers that have a high degree of participation in the training program in Mathematics and frequent use of the instructional material distributed in Portuguese. The conclusions of this work discuss the difficulties of conducting training programs, as a model for intervention in the academic performance of students in a concrete educational system through proposals of improving teacher qualification and the simultaneous follow-up of student achievement for a relatively long period. However, the study allowed to draw, from a particular experience at the State of Tocantins, suggestions and recommendations for public policies to improve the quality of Basic Education.

Teacher Training, improvement of student performance, public policies for improving the quality of basic education.