In Portugal, regardless of their school year, students are assessed at the end of each term in all subjects they are enrolled in. These assessments are called Internal Grades, or, to put it more simply, School Grades. In the last term of each year, students are given grades that reflect their teachers' assessment of their learning throughout the school year. These grades are, thus, the teachers' final account of the knowledge attained by their students throughout the academic year, based on test results and other forms of assessment.

School grades tend to vary less from year to year than national exams' scores. **While national exams can be used to measure the students' performance at a national level, school grades reflect the teachers' cumulative assessment of their students' performance** over one academic year. In fact, teachers' internal grades have proven highly stable when compared to the results achieved in external exams.

Data on students' internal grades are available in the National Examination Jury's database. However, these data only account for subjects in which students take national exams, i.e. 9^{th}-grade Maths and Portuguese, and 11^{th} and 12^{th}-grade national exams' subjects. This means that the data only represent the students who take national exams and not the entire student population. So that the data may be compared, the charts present the school grades of students who took the Portuguese and Maths exams, as internal students, under normal circumstances. In the results displayed for the 9^{th} grade, school grades correspond to the last school term, and for the 12^{th} grade, they reflect the average final grades of the 10^{th}, 11^{th} and 12^{th} grades combined.

Portuguese teachers have proven highly consistent in how they judge their students' learning based on national education benchmarks.

What do the figures tell us? Both for the 9^{th} and 10^{th} grade, the pattern of internal and final grades has not shown significant changes over the years. Since the pattern is constant, any small, systematic changes indicate progress in students' learning.

This can be seen for 9^{th}-grade Maths and Portuguese: the percentage of students attaining level 4 or level 5 (on a scale of 0 to 5) has been increasing since 2013/14.

Let us now look at the distribution of secondary school grades. Even though these figures only represent students who took national exams, as internal students, under normal circumstances, (as per the public access data source, which is the National Examination Jury database) some conclusions can still be drawn about how school grades have been evolving.

There has been a **gradual increase in the percentage of Top Performers in Maths, in both basic and secondary education, since 2013/14**. **This was particularly visible in 2017/18, where the median increased by almost 1 point.** This gradual change is mostly evidenced by an increase in the percentage of students attaining 15 points or more (on a scale of 0 to 20), which was recorded at 34% between 2009/10 and 2013/14, and then increased until it settled at 41% in 2017/18. In turn, **the percentage of students attaining 10 or 11 points (on a scale of 0 to 20), dropped from 34% (from 2009/10 to 2013/14) to 27% (in 2017/18)**. This trend becomes even more visible among the entire population of students: school retention rates are dropping among secondary school students, which means that the number of students exceeding the minimum grade to take exams (10 points) should be proportionally higher. However, significant changes have not been observed in the overall population of students due to an increased pursuit of vocational training; on the contrary, data show that the trend is for results to stabilise (and even decrease slightly).

The consolidation and consistency of teachers' assessment criteria, which is very much evidenced by the distribution pattern of school grades, indicate that there has been an improvement in students' learning, at least in Maths.

The distribution pattern of grades achieved by internal students who took the Portuguese exam, under normal conditions, has remained virtually unchanged over nine years (from 2009/10 to 2017/18). If the percentage of students exceeding the minimum grade required to take the national exams is increasing (which should be the case, since school retention rates for secondary students are dropping), this constancy in the distribution of grades attained by students who take the exams could also indicate an improvement in overall results.