What is STEM and why is it important?

Science, technology, engineering and mathematics, mostly known as STEM from the English STEM (science, technology, engineering and mathematics), are a group of subjects that underpin fields such as computer technology, biotechnology, medicine, pharmacy and many others. These are areas where there is expected to be a continuing need for research, innovation and the development of new products and solutions, and with this the demand for specialists in these fields is increasing. STEM subject education has an important role to play in preparing current and future generations to meet these needs.

This raises questions such as: How are Bulgarian schools doing in developing students’ knowledge and skills in STEM subjects? Are there significant differences between schools in different localities and regions of the country and why? Are there schools that stand out for their good performance in STEM that could serve as examples for other schools or for policy ideas? How are the numbers of pupils choosing to specialise in STEM subjects changing, and what indications does this give about how the demand for STEM specialists will be met in the next few years?

What does choosing a STEM subject for the second matriculation exam tell us?

With these questions in mind, we began looking at the data from the 12th Grade matriculation exams. This data allow us to see the number of students who chose a STEM subject for the second matriculation examination and the average matriculation score in that subject by school and by year. We stopped at this data because it is:* publicly available on the national portal for open data and are part of the database for linked data, which “Data for Good” maintains.

• at the school level, allowing differences between districts, settlements and schools to be analysed.
• available for the period 2016-2022, which allows to analyse changes and trends.

On the one hand, this data covers a specific part of the students in the country - twelfth graders who took a second matriculation exam in a STEM subject. If we want to track the general level of knowledge and skills in STEM, data covering all students or a representative sample of them would be more appropriate. On the other hand, the fact that this data reflects students’ choices makes them interesting and noteworthy.

Two factors are most likely to be behind the choice of subject for the second matriculation. First, students choose the subject for the second matriculation examination in which they expect to obtain a pass mark with the highest probability. This may be the subject in which they are best prepared, or the subject with the most favourable chances of success (’easiest’) in their opinion. The second reason for choosing a second matriculation is the use of results in university applications. If the results of a matriculation examination in a subject are accepted for admission to a degree programme, this may be a reason for it being chosen by students applying for that degree programme.

What does this mean for data interpretation? First, that the scores on a second STEM matriculation examination are expected to be higher than the STEM average if the more prepared students are the ones taking these examinations. Second, the proportion of students with a second matriculation in STEM may be an indicator of the proportion of students who are heading into STEM majors.

And here is what we see in the data for 2021.

Results at national level

In 2021, the average matriculation score in STEM¹ is 4.23. This is slightly below the average matriculation score in Bulgarian, 4.24² Just under half (47%) of those who took the second matriculation sat a matriculation in a STEM subject.

Results by districts

In order to compare the results across districts, we consider three parameters because each of them carries different information:

• Proportion of students taking the second matriculation exam in STEM subjects out of all students taking the second matriculation exam - a measure of the % of students who moved on to STEM subjects.
• Average score of the second matriculation exam in STEM subject - a measure of students’ level of knowledge.
• Difference between the average score of the second matriculation in STEM subject and the compulsory matriculation in Bulgarian Language and Literature - normalized measure of the level of knowledge. The hypothesis here is that “good” schools have high scores on all matriculation exams and, conversely, low-performing schools have low scores on all matriculation exams. This may explain many of the differences in average STEM matric scores, but also hide when a school’s STEM performance differs from its overall performance. Therefore, we use this parameter to measure how high or low a school’s average STEM score is relative to the STEM score we use as an indicator of overall school performance.

Бележки: Графиките представят средните стойности на ниво област за трите анализирани параметъра. При осредняването, стойностите на ниво училище са претеглени по броя ученици, явили се на втора матура по СТЕМ предмет.

Всяка от четирите области с най-много явили се на матура по СТЕМ (горе вляво) има по-висока средна оценка по СТЕМ от тази по БЕЛ (долу вляво). Кърджали и Търговище са примери за области с оценки по СТЕМ над средните за България (средно вляво), но техните успехи по СТЕМ са дори по-видими, когато се сравнят с резултатите им по български език (долу вляво). Можем да направим сравнение с област като Варна, където СТЕМ също е над средното за страната, но е под оценките по БЕЛ на Варна.

Кърджали и Търговище са двете области, които изпъкват с относително високо представяне и по трите параметъра. Там делът на явили се на СТЕМ матура е над средното ниво за страната – съответно 61% и 57%. Средната оценка е 4.52 и 4.53, а разликата със средната оценка по БЕЛ е най-висока спрямо всички други области – над 0.4 точки.

Област Смолян е с подобно представяне като % ученици избрали втора матура по СТЕМ и средна оценка. Различава се от другите две области по разликата в оценките между СТЕМ и БЕЛ, която е по-малка - 0.11.

Най-рядко са избрани матурите по СТЕМ предмети в областите Перник (25%) и Ямбол (27%). Средните оценки там обаче са близки до средната за страната (4.23). Най-ниски са средните оценки по СТЕМ матури в Столична община (3.60), Шумен (3.87), Хасково (3.92), Видин (3.95) и Стара Загора (3.97).

Как се разпределят тези средни оценки по училище виждаме на графиката по-долу.

Notes: Blue circles show the average STEM score at school level. Their size indicates the number of students who took the matriculation exam in STEM, which we use as a measure of school size by number of students. The red circles are the average STEM matric scores for the district, weighted by the number of students who took the STEM matric. Schools with the number of students taking a second STEM subject matriculation exam less than 5 are not shown in the graph.

In all districts across the country there is a wide variation in average scores. Almost all districts have a difference of at least 1.5 points between the highest and lowest scoring school. It is noticeable that the strongest performing schools are often mathematics or science high schools and the lowest performing schools are often vocational high schools.

Among the larger districts, it is striking that the strongest-performing schools in Sofia-City and to some extent Varna have higher average scores than the strongest schools in Burgas and to a lesser extent Plovdiv.

Questions for future research

These observations raise questions that we will try to answer in subsequent articles, such as the following:

• Are the differences persistent over time?
• What explains the differences by district and between schools?
• Can best practices be drawn from high performing schools? In particular, are there good examples among schools in smaller settlements, such as the high-performing schools in Kardzhali and Targovishte?