1. Introduction
The rapid development of information and communication technologies brings constant changes to industry, education, science and other sectors in the society. In these circumstances, individuals in various professions are expected to overcome problems and challenges they meet in a fast and efficient way. According to the World Bank, the global unemployment rate in 2021 was estimated at above 6%. In undeveloped countries, with a considerable percentage of non-educated people, this rate is even higher and equals more than 25% [
1]. The problem is additionally illustrated by the fact that about 40% of employers report the lack of an adequately skilled workforce capable of finding creative and integrative solutions for the problems they encounter [
2].
Various factors contribute to this situation, and one of them is certainly related to education. Educational systems in underdeveloped and developing countries do not usually correspond to the needs of the labour market. As a result, more and more companies organize trainings and other non-formal education courses for their employees. This situation implies that formal education must undergo serious changes, including the organizational segment of teaching and learning, to equip students with skills and competences needed for lifelong learning. The significance of the STEM approach for lifelong learning and education has recently been emphasized by a number of initiatives of American associations and European projects (e.g., INQUIRE, Mind the Gap, PRIMAS projects) that all recommend this approach for various educational levels, from pre-school to university education [
3].
In relevant literature, the STEM approach is described in various ways [
4,
5,
6,
7,
8,
9]. STEM education is an interdisciplinary approach to teaching and learning that removes traditional barriers among four disciplines: science, technology, engineering and mathematics, and integrates them into real-life relevant learning experiences for students [
10]. According to Dugger, 2010 STEM is an educational approach aimed at providing students with the ability to communicate in an interdisciplinary way, to do teamwork, to think creatively, to research, and to produce and to solve problems, focusing on the integration of knowledge and skills of science, technology, mathematics and engineering on an engineering design-based teaching [
11]. In the current study, the STEM approach in biology refers to teaching, learning and integrating the disciplines of science, technology, mathematics and engineering into scientific topics, with an emphasis on solving real-world problems. In this approach, students acquire key competencies and complex cognitive skills. These skills are needed for creating meaningful links in knowledge processing and result in interdisciplinary meaningful understanding. Interdisciplinarity is defined ‘as the capacity to integrate knowledge of two or more disciplines to produce a cognitive advancement in ways that would have been impossible or unlikely through single disciplinary means’ [
12] (p. 365). STEM approach is a radical step forward in relation to the traditional teaching and learning that is dominated by a non-STEM approach, in which frontal instruction takes place. Advantages of the STEM approach in relation to the quality of learning and establishing links between knowledge and real-life needs are numerous [
13,
14]. In real life, students face various problem situations and often tend to solve them from a single aspect, without considering the possibility of combining knowledge acquired in other areas and disciplines. Bearing this in mind, an interdisciplinary approach to teaching and learning is beneficial to students as it enables them to adopt a holistic view of everyday life affairs. This is the reason why the STEM approach is receiving more and more attention by science education experts and researchers [
15]. In an analysis of 28 studies, the authors conclude that the effect of the integrated approach through interdisciplinarity in teaching is positive in relation to the students’ achievement and outcomes of learning [
16]. According to Lamb et al. [
17], the levels of student self-efficacy, interests, spatial images, mental rotations and scientific knowledge were higher in STEM-group students in relation to their non-STEM peers. STEM activities also contributed to students’ cognitive and affective development. Another research study conducted by Cotabish et al. [
18] reports similar findings, as the STEM approach application contributed to a statistically significant increase in students’ understanding of the presented scientific processes in relation to the group with which a non-STEM approach was applied.
The rapid development of modern educational technologies and tools paves the way to new possibilities and ensures better conditions for STEM model application in the educational process. Smart boards, projectors, tablets and other devices have found their place in today’s classrooms and brought about the shift from a teacher-centred to a student-centred approach [
19]. Digital technologies have changed not only the learning styles of students but also their expectations in relation to the teacher and the learning environment [
20]. Students are eager to gain knowledge from various disciplines through gamification of the learning environment (the use of elements of video game design in the non-video-game context), as this environment is more interesting and engaging to them [
21]. Applications for assessing student knowledge such as Clickers, Kahoot!, Quizizz, Socrative, Zondle.com and many others are widely used in various levels of education today [
22]. A very popular tool in schools in Serbia today is Socrative, a tool for formative assessment. This tool allows a simple creation of various types of questions and thus enables revision of the taught content and formative assessment of students in a quiz-based manner. Students are given immediate feedback in relation to their answers, and the teacher has an insight into students’ scores, which helps them identify gaps in students’ knowledge [
23]. Other reasons for a wider use of these tools in the education process are the following: teachers can assess students’ progress and performance in real time; students have immediate feedback on their progress; other student skills that are difficult to develop in the traditional classroom are acquired and learning motivation and engagement of students in classes are increased [
24]. Socrative is a user-friendly application, does not require large investments in the equipment and has a multi-sided effect on the student-teacher interaction and the level of students’ motivation [
25]. At the same time, it stimulates and increases students’ active involvement in lessons [
26].
A successful integration of the STEM model in the educational process is affected by the students’ motivation, the teacher’s knowledge and attitudes toward the usefulness of this approach, their knowledge of the content of STEM disciplines, willingness to overcome potential barriers and commitment to creating an adequate environment for STEM teaching and learning [
27,
28]. However, many teachers are still not familiar with the context of STEM approach to teaching, which requires the integration of knowledge, skills and values of the STEM disciplines by means of various strategies, such as scientific research and project-based learning that are used for solving real-life problems [
15,
29]. As a result, students are mostly guided by their teachers from a monodisciplinary point of view [
30]. Therefore, the implementation of the STEM approach may include pedagogical or structural challenges, limitations of the syllabi, students’ resistance to accepting new concepts and insufficient support from administrators and policy makers [
31,
32,
33], which is similar for implementing various teaching approaches within individual school subjects [
34]. Insufficient general guidelines for teachers how to integrate STEM in their lessons is also a challenge [
35]. In the USA and developed European Union countries, many of the barriers to the STEM approach application have been removed, and the approach has become part of regular educational practices in high-ranked schools [
11,
36].
As the STEM approach has a potential for improving twenty-first century skills, its implementation should be continual from the earliest age to the highest levels of education [
37]. So far, STEM education research has mostly focused on the effect of this approach on students’ performance and/or their views and experiences, as well as on scientific process skills [
11,
38,
39,
40]. Most of the studies have taken place in higher grades of primary school education or within the context of high school education [
41]. A wider-scope literature review on the efficiency of an educational approach shows that for obtaining more valid findings, many researchers take into account the mental effort that students employ in solving tasks, apart from measuring their performance [
42,
43,
44,
45,
46]. By combining the values representing students’ performance and the level of mental effort they invest, the instructional efficiency of an educational approach is obtained [
47]. Additionally, in another study it was elaborated that by combining the values of mental effort and students’ performance, involvement of students in the applied teaching approach can be assessed [
48]. An efficient approach is therefore the one that implies a greater performance and involvement of students and less investment of their mental effort at the same time. Mental effort is an aspect of the cognitive load which is related to cognitive capacities distinguished by the processing requirements of the task [
49]. The level of mental effort is determined by the characteristics of the tasks and the applied approach [
50,
51] and can be measured both subjectively and objectively. According to Milenković [
52], the objective assessment mostly implies some physiological or behavioural measurements, and some of the most frequently used techniques for objective measurement include eye tracking [
53], brain activity measurement [
54] or the control of cardiovascular indicators [
55]. As for subjective measurement, one of the most widely used techniques among researchers is based on the assumption that individuals are capable of assessing their cognitive processes and assigning numerical values to the mental effort they invest [
49]. Numerous authors believe that measuring the self-perceived level of one’s mental effort on scales with seven or nine points represents the most suitable method of measurement in school settings, as it is sufficiently reliable and at the same time simple and easy for use [
56,
57]. The use of the Likert scale as a reliable instrument for measuring the level of mental effort has been documented by a large number of authors [
58,
59,
60,
61,
62]. All these authors claim that this type of scale is among the most reliable and most precise scales for detecting very slight changes in the level of invested mental effort. This view has been additionally supported by Moray and O’Donnell, as cited in Kalyuga et al. [
61] and Eggemeier [
56], who found that subjective assessment of the invested mental effort highly correlated with objective measurements (the correlations were within the range 0.80–0.99). In addition, Kalyuga et al. [
61] emphasized one more advantage of these rating scales, and that is that their use does not disturb completion of tasks, as is case with other techniques, such as the use of a secondary task [
52].
With the intention of developing key competences for lifelong learning among students in the Republic of Serbia, the STEM approach has recently been introduced in the educational process in a few private secondary schools. In all primary schools in Serbia, STEM disciplines are not taught as an interdisciplinary subject, science, but rather as individual school subjects: biology, physics, chemistry, mathematics, etc., [
63] and studies related to the efficiency of the STEM approach in biology teaching are scarce. The present research is aimed at determining the efficiency of the STEM approach in biology teaching in primary school and the promotion of this approach in the educational system. The obtained results can serve as guidelines in creating the national education policy that would align with the latest world trends in education.
2. Research Methodology
The aim of the present study is to determine the instructional efficiency and student involvement in applying the STEM approach in primary school biology teaching, compared with the conventional, i.e., non-STEM approach. The efficiency is assessed in relation to the students’ test performance, their perceived mental effort invested in solving test tasks and their involvement. Correspondingly, the following research questions are addressed:
Which approach, STEM or non-STEM, increases the students’ performance and maintenance of the functional knowledge in biology teaching?
Which approach, STEM or non-STEM, shows greater efficiency considering students’ perceived mental effort in solving tasks on tests of knowledge in biology teaching?
Which approach, STEM or non-STEM, results in higher values of educational efficiency and students’ involvement?
To address these questions adequately, the research design employed in the study included the pedagogical experiment with parallel groups (experimental and control). Students in the experimental group (E) were instructed by STEM integration in the seventh grade biology classes, whereas at the same time, their peers in the control group (C) were taught the same contents applying the conventional, non-STEM method. The two groups were then evaluated to identify effects of the applied teaching approaches on the students’ performance and their assessment of the mental effort invested in completing the knowledge tests.
2.1. Sample
The convenience sample consisted of 180 students, divided into two groups: 90 in the experimental group and 90 in the control group. Both groups consisted of three classes of seventh grade students, all between ages 13–14, who attended two public primary schools in the city of Novi Sad. The experimental group comprised of 43 boys and 47 girls, whereas in the control group there were 41 boys and 49 girls. Considering the use of Socrative as formative assessment tool in the E group, prior to the research period it was established that none of the students in this group lacked a mobile device that could be brought to school, which enabled them to participate in the research. The school in which the experiment was performed had a stable internet connection accessible to all teachers and students.
For conducting this research, an informed consent from the school headmasters, teachers, counselors, school boards and all participants and their legal guardians was obtained.
2.2. Instrument and Procedure
The experiment was carried out in the second semester in the school year 2020/21, during eleven regular biology lessons, each lasting 45 min. The lessons focused on the subtopics ‘Digestive system in Humans’, ‘Circulatory system in Humans’, ‘Respiratory system in Humans’ and ‘Urinary system in Humans’ (‘DCRU’), all of them being part of the seventh grade primary school curriculum. Each subtopic was covered by two lessons. Thus, the subtopic ‘Digestive system in Humans’ was dealt with in two lessons entitled ‘An overview of evolutionary diversity of digestive system organs in animals’ and ‘Structure of digestive system organs in humans and some diseases of digestive organs’. Within the experimental period, eight lessons included the presentation of the contents, two lessons served as a revision, and in the last lesson students did the posttest.
Two biology teachers, permanently employed in two primary schools, participated in the study. Prior to the experimental period, the teacher employed in the experimental school attended a continuous professional development course on the application of the STEM approach in biology classes. The course was given by a team of authors of an accredited program for continuous professional development of teachers, and one of the authors of the program is an author of the current research.
At the beginning of the research, both the E and the C group students took a pretest in order to synchronize the previous knowledge necessary for acquiring the contents related to the four systems of organs in humans (‘DCRU’). The pretest was done with both groups on the same day. It contained 18 multiple choice items, with each correct item scoring one point, thus making the maximum pretest performance of 18 points. The items required the use of knowledge gained within the subject biology in the previous school year, and they all referred to the four systems of organs. In primary schools in Serbia, the biology curriculum is spirally organized. This means that students study the same contents from the grades 5 to 8 (ages 10–14), each year in a more in-depth manner and with a gradual increase in applying logical and methodological operations. The curriculum is oriented toward learning outcomes, which gives freedom to the teacher in creating and designing the teaching process. This kind of organization also allows freedom in choosing learning approaches and techniques, as well as the activities that are applied for developing and integrating knowledge into meaningful wholes. This approach to the planning of the teaching and learning processes allowed conducting an experimental study that aimed at examining the instructional efficiency of STEM and non-STEM approaches in biology teaching.
STEM classes in the E group were organized in the following manner: 1. In an introduction to the class (10-min duration) the teacher encouraged students to think about the content to be taught by asking questions addressed to the whole group. For example, in the class devoted to air and respiratory system, the following questions were asked: “How do fish breathe in water?”, “What about animals that live on land?”, “Why do we keep breathing?”, and in this way the students were guided to understand the importance of air for life; 2. The next segment of class included a group activity (10-min duration) in which students had to answer some problem-based questions encompassing various aspects of the concept that was taught. In answering these STEM questions, the students relied on background knowledge, and the teacher directed them on how to search for relevant information on the internet and emphasized the reliable sources on the web. The problem-based STEM questions that groups of students were supposed to answer in several classes during the experimental period were: “Which factors determine the amount of oxygen in water and on land?”, “In what way can oxygen be obtained from water?”, “How does air enter and leave our body?”, “Why do we breathe in air?”, “Why do we consume food?”, “What happens in the fusion of oxygen and other substances (e.g., metal, food in organism…)?”, “What is implied by the reaction of oxidation and reduction of organic solutions?”, “In what way the oxygen we breathe in is distributed to all tissues in the organism?”, “In what way the energy obtained by cell breathing affects our body temperature?”, “What is atmospheric pressure?” and “What is partial pressure of oxygen in the artery blood?”. Groups of students were given a mathematical problem to solve; based on the number of breaths per minute in a newborn in static posture and the information on the decreased number of breaths in an adult in static posture, students were expected to calculate the number of breaths per minute in an adult in a specific period of time. The E group students were also introduced to the functioning of some technological instruments (spirometer, blood pressure monitor…) to better understand the importance of these devices for human health. They were also given some questions related to this topic, for example ‘What do the values displayed on the blood pressure monitor represent?’ In addition, there were some practical assignments for them, such as the measurement of their pulse rate while resting and then after doing 15 and 30 squats. They were supposed to mark these measurements on a chart, and after this there was a class discussion and analysis of the completed task. 3. In the following class segment, discussion for findings (15-min duration), the group spokespersons presented their group findings and discussed them actively with other classmates while the teacher directed their discussion. In this discussion, the teacher could see what dilemmas the students had and solved them in further discussion with the students. The teacher asked additional questions to the whole class in order to assess how well the students understood the concept (e.g., “Is the structure of inhaled and exhaled air the same?”, “Which air contains more carbon dioxide?”) 4. In the final part (10-min duration), the students individually did a knowledge test using the Socrative online tool for formal assessment. Each test included five questions of various types that served to assess the acquisition of the STEM concept taught in the lesson. While the students were doing a Socrative test, the teacher monitored their answers, and upon the test completion, the answers to incorrectly solved questions were given by other students and/or the teacher.
The structure of non-STEM lessons in the C group was similar to the one in the E group (introduction, group activity of students, discussion for findings, Socrative online tool for formal assessment), but in all these segments the STEM concept was not applied. Instead, the lesson contents and problems were approached and dealt with only from biological aspect, i.e., the students did not approach scientific concepts in an interdisciplinary way, using the knowledge from various disciplines. In such a way, the scientific concepts were taught through several separate subjects—biology, geography, physics and mathematics.
Upon the completion of the analysis of the teaching subtopics ‘DCRU’, students from both groups took a posttest on the same day. The posttest contained 18 multiple choice items. Each correctly completed item scored one point, thus making the maximum performance score on the test 18 points. The items measured the achievement of the learning outcomes specified by the seventh grade biology curriculum. The learning outcomes required students to connect the learning content with already acquired knowledge and everyday life situations, as well as to interrelate new knowledge with previously taught content in biology and other subjects by applying problem solving techniques. Both groups (E and C) did the same test, as this enabled comparison in potential differences in the achievement of the learning outcomes after the implementing the two teaching approaches. Then, 90 days after the posttest, both groups did a retest (the repeated posttest) that had not been announced. The goal was to assess the retention of the achieved learning outcomes in both groups. Within each posttest/retest item, the students were asked to rate the level of mental effort they invested in solving the items. They evaluated the mental effort by selecting one of the offered descriptors on the 7-point Likert scale. The descriptors were coded in the following way: from extremely easy (code 1) to extremely difficult (code 7). The posttest (retest) items were problem-based tasks and required a good understanding of biological contents. Examples of several posttest items are presented in
Appendix A. The Cronbach’s alpha values obtained for the posttest was 0.818 and for mental effort was 0.960.
2.3. Data Analysis
Although the values of skewness and kurtosis are within the range ± 2, the Shapiro-Wilk test of normality showed a deviation from the normal distribution, and that is why non-parametric tests were applied. The Mann-Whithey U test was used for examining the differences in students’ performance and the invested mental effort between the E and C group participants. For examining the differences in scores in repeated measurements (the pretest, posttest and retest) within a group, the Wilcoxon signed-rank test was applied. Additionally, based on the standardized values of performance and perceived mental effort the instructional efficiency and students’ involvement were calculated for the applied teaching approaches. Data were analyzed using SPSS 20.0.
4. Discussion
The STEM approach is based on the development of students’ creativity potentials, solutions to complex problems and, above all, on real life interactions. In the USA, Australia, China and some Scandinavian countries, STEM education is by and large integrated in the educational systems. In schools in Serbia and its neighbouring countries, science teaching and learning is done through separate, individual subjects such as biology, chemistry, physics and geography, whereas technology is part of the school subject technical and information education, and mathematics is a subject in its own right. Studying all these subjects individually, without interrelating them, students do not develop key skills and competencies important for advancing in the modern society. These education systems therefore require a shift in the education paradigm based on contents teaching and a radical move towards achieving the learning outcomes and interrelations among subjects, i.e., towards STEM approach application. This, of course, does not imply an emergent education reform and immediate introduction of STEM approach, but a gradual implementation of this model in the school curriculum where the teaching content is based on the selection and presentation of examples and experiences in which various disciplines are interrelated. Considering that the STEM approach is hardly employed in schools of Serbia and its neighbouring countries, the idea of the usefulness of this approach needs to be empirically supported. Accordingly, the present study is aimed at examining the efficiency of the STEM approach in primary school biology classes in comparison with a non-STEM approach.
The first obtained result in this study indicates that students who acquired biological concepts using the STEM approach showed better performance on the posttest and the re-test compared to their peers who were taught by a non-STEM approach. Students’ performance was measured by means of a multiple-choice test, and both test results showed that performance scores of the STEM group were significantly higher than those of the non-STEM group. These results are supported by the research findings that emphasize a positive effect of the STEM approach on students’ performance [
16,
64,
65,
66]. In the study with fifth-grade primary school students, Karci [
67] found that the effects of the STEM approach are positive, significantly improve the students’ academic achievement and raise their interest in STEM approach and motivation for science learning. In another study that analyzed 38 studies on the effect of STEM education on the academic achievement of students, a general conclusion is that this approach has a very beneficial effect on academic success [
68]. A relatively small number of studies focused on the effect of the STEM approach on knowledge maintenance. The findings of the current study are in line with the findings reported by other authors [
69]. According to these authors, through student-centred activities, meaningful knowledge is obtained and retained for a long period of time. Apart from knowledge maintenance, the STEM learning environment increases motivation for learning and preserves it for a long period of time [
70].
The second obtained result indicates that the application of the STEM approach in biology teaching requires less mental effort of students in task dealing than in the case when non-STEM approach is applied. Less mental effort investment by the E group students and their better performance on the posttest and the retest could be explained by several reasons. One of these refers to the way of studying biological concepts based on direct experiences and examples from everyday life. Further, the teacher encouraged problem solving by asking problem-based questions that related to common situations in students’ lives, and when finding solutions to these problems students had to rely to various subject areas and integrate them. In the first few lessons of the experimental period, students had to additionally engage in the learning process, as the current results demonstrate, and this led to gaining functional and applicable knowledge. When collaborating in class, the students were encouraged to ask additional questions, express their opinion about solutions to problems and discuss about biological concepts in the STEM manner. This finding was supported by Kong and Mohd Matore [
71], who evidenced that the implementation of the STEM approach that involved problem-based learning was effective and improved the students’ mathematics performance in comparison with the performance by the non-STEM approach. The authors conclude that the greater posttest mean-score was due to the increased student interactions and engagement in STEM classes. Apart from contributing to higher students’ performance, other studies [
72,
73] also show that the STEM approach can attract students’ attention and increase their interest and positive attitude towards learning. Contrary to this practice, the non-STEM approach implies separate subject content teaching. The C group students were mostly passive in classes, and the knowledge they acquired was only from the biological aspect, without interrelating it to other disciplines. The frontal teaching dominated and thus the teacher’s role was overemphasized, which left very little space for students’ activities and engagement. The findings pointing to less mental effort investment and better posttest performance in classes with more student engagement in applying innovative teaching approaches have been confirmed in a number of studies [
42,
45,
46,
74,
75].
The E group’s higher performance and less mental effort investment could have also been caused by the way in which students revised the content, i.e., by immediate feedback on their progress obtained by completing Socrative quizzes at the end of each lesson. As a result of using technologies that students are familiar with and fond of, their motivation for learning becomes greater. Socrative is one of many applications that are very appealing to students. When using Socrative in class, time management for learning is better and students receive immediate feedback on their learning [
76], and its focused environment leads to better performance of students [
77,
78]. Although the C group students received feedback when completing Socrative quiz, it was noticeable that they lacked complete understanding of the problems from an interdisciplinary angle.
The obtained positive values of the instructional efficiency and the students’ involvement indicate a high level of efficiency of the STEM approach in biology teaching in primary school. Although the current findings corroborate with positive results of other studies stated above and point to a considerable effect of the application of the STEM approach in the classroom, there are also studies that report positive results of the STEM approach in an online environment, which has shown as particularly useful during the COVID-19 pandemic [
79]. Considering the fact that education is currently in between online and offline approaches and that there is an increasing trend in the application of hybrid educational models, further research should encompass already reported positive experiences with the STEM approach and develop strategies for its application in online environment. The presented results should also be analyzed in terms of the study limitations, such as a relatively small sample (180 students) and a small amount of the content covered by the pedagogical experiment.
Additionally, it should be stated that the STEM approach is still insufficiently explored and that in many countries teaching of separate subjects still prevails. This implies a need for continual research on the effects of STEM approach, not only in biology teaching, but in other subject areas as well. The further research findings would bring more valid conclusions, recommendations and strategies for implementing this approach in the educational process. In order to implement it successfully in the education systems worldwide, it is necessary to supply schools with resources and to educate teachers how to apply this approach through programmes of continuous professional development and examples of good practice. It would also be useful to compare the efficiency of the STEM approach with other innovative approaches that have proved beneficial in teaching individual school subjects [
46,
75,
80,
81,
82] to find a teaching approach that best suits students’ needs.