The Chilean public school is being strongly criticized because low school achievement. This situation, associated to strong tendencies in Chile to privatization of the school system, implies today a question about its survival. This study represents a contribution to the analysis of the causes of low school results and it aims to suggest some measures in order to fortify the public school through getting better school outcomes. The central thesis is here that the public school has the capacity to confront the negative influence of working with students from poor settings, and showing that also unprivileged students may get high school performance. Methodologically this study is based on quantitative analysis of associated factors to school results using a probabilistic sample of public schools. An important methodological suggestion is that to work with normal distributed results is not the best way to get explanation but it should be completed with an analysis of extreme cases, outliers.
The results show that external factors like cultural capital are very significant and predictive, but more important are internal factors, processes occurring at the school class, especially emotional interactions between teachers and students. Finally, the results point to gender discrimination, eliciting better results for boys, in mathematics than for girls. This study suggests that the public school would focus girls´ results as a way to enhance global school results.