1. Introduction
Atoms and molecules are fundamental concepts in chemistry, and therefore, are regarded as core topics in the South African Curriculum and Assessment Policy Statement (CAPS) for physical sciences [
1]. Atomic structure encapsulates concepts such as models of the atom, atomic mass and diameter, protons, neutrons and electrons, isotopes, energy quantization and electron configuration, while molecular structure covers a chemical bond, molecular shape, electronegativity and bond polarity, bond energy and bond length. Engagement in atomic and molecular structure provides an opportunity to kindle learners’ interest in the subject matter [
2]. For example, it introduces the idea that all matter consists of small indivisible particles called atoms, which are so small that they cannot be seen by the human eye. Questions exchanged between teacher and learner can invoke the imagination and curiosity of learners to investigate further to formulate an understanding of such phenomena [
3].
Due to students’ inability to perceive the atom, this contributes to the complex and abstract nature of chemistry, thus making the study of the subject difficult for students [
4,
5,
6]. A study conducted by Cokelez [
7] involving sixth grade and seventh-grade learners showed that they have difficulty developing a mental model about the concept of the atom, with many likening the atom to a sand particle. Similarly, Harrison and Treagust [
8] (p. 509) revealed that younger science students have difficulty separating models from reality, with students concluding that “atoms can reproduce and grow and that atomic nuclei divide”. This difficulty is persistent with even university students still lacking the basic knowledge of what atomic structures and the atomic theory is essentially made up of [
9]. Furthermore, a study by Kiray [
10] demonstrated that pre-service science teachers had difficulty grasping the atom, electron cloud, and orbital concepts. According to Derman, Koçak, and Eilks [
11], there is no unanimous agreement on how these topics should be taught in schools, with different approaches being employed by teachers. However, it is generally acknowledged that the “use of various models and corresponding visual representations in science classes are necessary and beneficial” [
11] (p. 3).
The increasing availability of computers and related equipment, such as smartboards and mobile devices, and the corresponding availability of software, such as simulations, especially in science, has resulted in simulations becoming an integral part of science teaching and learning [
12]. Teachers use appropriate pedagogical representations, such as computer simulations, which may aid in making these abstract concepts, such as atomic and molecular structure, more accessible to learners [
13]. These simulations allow learners to individually construct knowledge on atoms and molecular structures, fostering deep conceptual learning [
14]. Simulations allow learners to use their own knowledge and learn through inquiry, thus eradicating the idea that the teacher is the only source of information in a classroom, and recognizing learners’ prior knowledge as important for concept formation and understanding of atomic and molecular structures [
15,
16].
2. Simulation-Supported Scientific Inquiry
Inquiry-based science education has been at the cornerstones of school science curriculum reform. The importance that is given to inquiry in the South African curriculum is underlined through Specific Aim 2 of the Curriculum and Assessment Policy Statement where it is stated that “Learners must be able to plan and carry out investigations as well as solve problems that require some practical ability” [
1]. Inquiry is often regarded as a fluid construct due to multiple interpretations and perspectives. There is some consensus that scientific inquiry is considered as, “…the diverse ways in which scientists study the natural world and propose explanations based on evidence derived from their work” [
17], and “the process by which scientific knowledge is developed” [
18]. Pedaste et al [
19] further elaborate that inquiry-based learning is a teaching approach which allows learners to learn through being actively involved in their learning instead of trying to memorize what is being taught to them by their teacher.
Studies have reported the benefits of inquiry-based teaching such as that inquiry-based learning experiences stimulates interest in science [
20,
21], improves understanding of concepts [
22,
23], leads to an understanding of the nature of science [
24], leads to the development of higher order thinking [
25], facilitates collaboration between learners [
26] and helps to develop experimental skills [
27].
Inquiry-based learning enables learners to be active participants in investigations, making decisions about how and what they learn, identify where they are, engage in active thinking and draw conclusions from the data they have collected [
28]. Computer simulations offer an environment for learners that is suited for inquiry, due to the fact that they allow learners to question and explore through experimenting with the simulations [
29,
30]. Computer simulations can be integrated into inquiry learning environments to supported learners in their investigations. Research shows that simulation-supported scientific inquiry can improve learners’ conceptual understanding [
31]. Studies also reveal that students taught science through simulated inquiry-based learning outperformed those using traditional instruction [
32,
33]. Furthermore, when simulations are used in relation to the 5E inquiry instructional model, significant conceptual change can take place to remediate students’ misconceptions [
34,
35].
3. Integrating Simulations in South African Classrooms
Simulations can support learning when applied correctly in a classroom. Teaching with simulations is different from using a traditional direct teaching approach as simulations allow learners to learn through discovery, thus fostering a sense of deep learning instead of surface learning amongst learners [
14,
36]. Simulations also enhance the visualization of phenomena, especially when they are coupled with practical activities [
37]. Simulations can present rich visual displays of molecules and atoms to support learners in their understanding of chemical phenomena and their interactions [
38]. This also leads to an increase in a learner’s motivation to study the subject matter [
39], which may subsequently make learners participate more and become more active learners in class, as increased learner activity is one of the results of using an inquiry-based approach [
19].
The integration of ICT in classrooms, though being beneficial, holds many challenges for both learners and teachers. In order for teachers to be effective in teaching with technology, there is a strong need for the training of teachers with these devices [
40]. Training will, therefore, allow teachers to broaden their technological pedagogical knowledge and, in essence, enhances their ability to choose the correct type of simulations and recognize its pedagogical value. Despite the aforementioned benefits of simulations, the socio-economic context of a country may impede its implementation. This is certainly the case in a country such as South Africa where only 10% of the 28,000 schools in South Africa have access to at least one computer [
39]. Most schools in rural areas of South African already struggle with issues of overcrowded classrooms, lack of adequate furniture and even a shortage of textbooks. Some of the challenges cited in South Africa include a lack of teaching time, resource inadequacy, large classes, and safety concerns [
41]. The affordances of technology, such as simulations, are therefore largely unexplored within the South African context. The use of simulations could provide an alternative to traditional laboratory experimentation that has been constrained due to the aforementioned challenges.
This study investigated how inquiry-based simulations can enhance South African grade 8 natural sciences learners’ understanding of atomic and molecular structures. Accordingly, the research was guided by the following two research questions:
How does simulation-supported inquiry learning enhance grade 8 learners’ understanding of atomic and molecular structures?
What are learners’ perceptions and experiences of using simulations in making scientific inquiry?
4. Research Design and Methodology
The study adopts a mixed-methods approach, which uses a combination of quantitative and qualitative research approaches. Johnson and Onwuegbuzie [
42] describe mixed methods research as the third research paradigm after the quantitative and qualitative paradigms. They state that “the goal of mixed methods research is not to replace either of these approaches but rather to draw from the strengths and weaknesses of both in single research studies and across studies” (p. 14). Mixed methods research is described by Johnson and Onwuegbuzie as “the class of research where the researcher mixes or combines quantitative and qualitative research techniques, methods, approaches, concepts, or language in a single study” (p. 17).
In addressing the first research question, a simple randomized control trail (RCT) was followed. According to Hariton and Locascio [
43], randomized control trails enable comparison between an experimental group and control group in order to determine the effect of an intervention (such as a simulation) on a learning outcome (such as learner understanding of atomic and molecular structures).
Two similarly academically performing grade 8 natural science classes were randomly chosen as the control class and the experimental class. The learners in each class were also similar in terms of their prior schooling, their first language spoken, and the community they resided in. The learners in the control class were taught atomic and molecular structure by means of a traditional direct teaching approach, whereas the experimental class experienced inquiry-based learning that was facilitated by the use of simulations. Both the control and experimental classes made a structured inquiry on where they investigate using models to build atoms, molecules, and compounds. The investigation was structured in that the teachers provided them with a worksheet that prompted them on what needed to be done. Therefore, while the control class used physical models to build, draw, and investigate the structures, the experimental class used a simulation.
The simulations for this research study were sourced from the Physics Education Technology (PhET) project. PhET was developed by a group of researchers from the University of Colorado at Boulder in the United States of America. The PhET simulations are highly interactive and provide animated feedback to the user. These simulations are freely available on the internet and, therefore, accessible to all South Africans. In addition, the PhET simulations can be downloaded onto a computer or laptop and then used without internet connectivity. The PhET simulation experiences by the experimental class were called “Build a molecule” and can accessed by the link
https://phet.colorado.edu/en/simulation/build-a-molecule. The following learning goals are provided for this simulation: Describe the differences between an atom and a molecule, construct simple molecules from atoms, recognize that the subscript in the molecular formula indicates the number of that atom in the molecule, recognize that the coefficient indicates the total number of molecules, associate common molecule names with multiple representations.
Figure 1 is a screenshot of this simulation.
Quantitative data were collected by means of a pretest on a topic already taught and a posttest that was comprised of items that tested the conceptual understanding of learners on atomic and molecular structures. The items were sourced from tests and examination questions papers that were set by the South African Department of Basic Education. The items were, therefore, valid. The pretest was comprised of six multiple-choice items, and the maximum attainable score was 8, while the posttest had eight items and these totaled a score of 8 as well. An example of such an item is: A particle that cannot be broken down further is A. compound B. mixture C. element D. atom. See
Appendix A for the pretest and posttest. In both tests, students were expected to demonstrate the following capabilities: Understand that atoms are indivisible, identify sub-atomic particles of an atom, identify examples of compound and diatomic molecules, and differentiate between atoms, elements, molecules, and compounds.
The second research question was addressed by means of a questionnaire survey that was administered to the experimental group after the intervention. The questionnaire solicited learners’ perceptions and experiences of using simulations in inquiry learning. It was developed by the authors. It was distributed to two researchers in science education for comment on its construct validity. Both researchers commented that the items addressed the intention of the questionnaire. The questionnaire was comprised of five-point Likert scale items, where the options ranged from “1 = strongly disagree” to “5 = strongly agree”. Learners from the experimental group were selected for interviews, whereupon elaboration was sought on the questionnaire responses. These learners were asked to describe their experiences of engaging with the simulation and to identify how this experience was different from a traditional learning experience. The interviews were transcribed for analysis.
The tests yielded quantitative data that were analyzed statistically using SPSS software to yield descriptive statistics, such as the mean, standard deviation, and standard error of the mean. Inferentially, the mean test performances of the groups were compared by
t-tests. The
t-test was considered appropriate as it is used to assess the “statistical significance of the difference between two sample means for a single dependent variable” [
44] (p. 442). The independent-samples
t-test was conducted by firstly comparing the mean scores of the experimental and control groups in the pretest, and secondly, it was used in comparing the mean scores of these groups in the posttest. Questionnaire data were analyzed descriptively by computing frequencies in responses to the Likert scale and then percentages on these responses.
The qualitative interview data were coded to generate themes [
45].
Coding is a research method that a researcher uses when interested in utilizing an entire dataset to identify underlying themes presented through the data [
46]. This process entailed firstly reading through the data, in order to get a global overview. Thereafter, excerpts were coded and then placed into categories. The codes were not predetermined but emerged from the data. After coding all the data, the codes sharing the same meaning were grouped together into sub-themes, which were eventually grouped together into themes.
Table 1 is an excerpt from the coding book that was developed. For example, the codes “Visual nature of simulation” and “Pictures are better than words” shared a similar meaning and could be placed in the category “Simulations and learner understanding”, leading to the theme “Simulations support learner understanding”.
Ethical clearance to conduct the research was granted by the ethical clearance committee of the university that the researchers are affiliated with (number 2018-041). All participants provided a written consent for data collection. The teachers and learners were informed that they could withdraw from the study at any time. They were also assured that their identity, the identity of the school, and responses would be kept confidential.
6. Discussion and Conclusions
The study investigated whether computer simulations in inquiry learning enhanced learners’ understanding of atomic and molecular structures. The findings revealed that the experimental group performed better than the control group. It is evident that an inquiry-based approach using a simulation was a more effective approach compared to a traditional direct teaching approach where learners were largely inactive. The findings of this study correlate with the results of other studies (e.g., [
29,
30,
35,
47]) that found positive impacts of learner inquiry with simulations on learners’ understanding of science concepts.
Furthermore, as can be observed from their assessment questionnaire responses, learners consider that the use of ICT, together with the methodology used, has facilitated their learning and has encouraged them to study chemistry and learn more [
48]. However, in addition, a relevant aspect of this classroom experience is that, presumably, it favors lifelong learning, since a large percentage of students indicate that “After using simulations, I would want to try using other computer-assisted learning programs”. However, this aspect will be explored in depth in further research.
The findings could be of significance to South African science classrooms because as pointed out by Author [
49], South Africa’s education system, similar to other countries, follows a high-stake assessment system, which often results in teachers “teaching to the test”. This, therefore, may result in learners only developing a surface understanding of content taught as opposed to learners experiencing a sense of deep learning. Simulations may also provide a viable alternative to physical laboratories that exist in only a small proportion of South African schools. The findings of this study reveal that incorporating the usage of simulations in a science classroom allows learners to experience a more enhanced understanding of the content learned. The value of simulations, as revealed from the results of this study, is that they enable visualization of phenomena that are ordinarily encountered as abstract by learners. By means of visualization, learners acquire an understanding of such phenomena. In particular, the findings of this study reveal that simulations can be exploited in providing viable inquiry-based learning experiences for learners.
International assessments, such as the Trends in International Mathematics and Science Studies (TIMSS), repeated over the years from 1990 to 2003 show that the performance of South African learners in and science, especially black learners from impoverished communities, such as townships, is alarmingly poor compared to other developing countries [
50]. More recently, the World Economic Forum report for 2015/16 painted a dismal picture, with South Africa placed at 138 out of 140 countries. The findings of this study invite further investigation in a large-scale study on the impact simulated inquiries may have in addressing the poor performance of learners in science. Future studies should also focus on other topics where concepts are abstract, and that challenge the visualization of learners.