Noor Haslina
Daman Huri
and
Mageswary
Karpudewan
*
School of Educational Studies, Universiti Sains Malaysia, Penang, Malaysia. E-mail: n_haslina@hotmail.com; kmageswary@usm.my; mageswary_karpudewan@yahoo.com
First published on 24th April 2019
STEM education is gaining increasing attention globally to fulfill the acute shortage of STEM workforce. Executing STEM education is frequently viewed as a complex and challenging agenda. The current study proposes Integrated STEM-lab activities in the teaching and learning of electrolysis. The activities use real-world contexts as a platform to exhibit the transdisciplinary nature of integration of the four STEM disciplines. Embedded mixed methods research used quantitative one group pre-test–post-test design, and qualitative interviews were employed to measure the effectiveness of the Integrated STEM-lab activities in improving 50 secondary school students’ (Form Four equivalent to Grade 9) understanding of electrolysis. The Electrolysis Diagnostics Instrument was administered for pre- and post-tests. One-way Multivariate Analysis of Variance (MANOVA) revealed that the Integrated STEM-lab activities effectively improved the students’ understanding of electrolysis measured in three subscales (Wilks’ lambda = 0.664;F(3,96) = 16.164; p < 0.05; η = 0.336) with 33.6% of the variances in the pre- and post-tests explained by the treatment. The qualitative interview data supported and provided insight into understanding the quantitative findings. In the interviews, the students elaborated their understanding of electrolysis with details, and consistently the activities were referred to in their responses. The findings of this study suggest that Integrated-STEM lab activities are suitable to address the limitation of the existing laboratory activities for knowledge construction. The activities are exemplary for integrating the four STEM disciplines into the standard science curriculum.
Many studies have suggested Integrated STEM as a distinct subject possibly taught using project-based learning (Han et al., 2015; Erdogan et al., 2016; Han et al., 2016; Lou et al., 2017), problem-based learning (Asghar et al., 2012; English, 2017; Lou et al., 2017), and community-based after-school programs (Jho et al., 2016; Sasson, 2018) and through the formation of STEM education centers (Carlisle and Weaver, 2018). Integrated STEM as a separate subject outside the formal education has been successful and the participants have benefited from the initiatives. Having Integrated STEM in isolation as a single subject outside the formal education demands provision of extra time for learning the subject, and often students are less interested in learning outside of the curriculum as it adds on to the overwhelming amount of content learned during the formal schooling hours (Rickinson, 2004; Dyment, 2005; Waite, 2011). In contrast, Integrated STEM Education is well presented if the learning objectives of the standard mathematics and science curriculum (Moore et al., 2014; Moore et al., 2016) are taught at an increasing level of boundary crossings along the continuum of the four STEM disciplines (Vasquez et al., 2013) for meaningful learning. However, integrating the four STEM disciplines into existing subjects frequently has been a challenging task for educators. One of the profound constraints is that teachers lack the knowledge on embedding the four STEM disciplines into teaching the subjects (English and King, 2015; Kelley and Knowles, 2016; Radloff and Guzey, 2016; Chalmers et al., 2017).
The effectiveness of laboratory activities in enhancing conceptual understanding is ambiguous (Hofstein and Lunetta, 2004; Abrahams and Millar, 2008; Abrahams and Reiss, 2012). The current science laboratory guide offers a ‘cookbook’ procedure for students to ritually follow without engaging them in thinking and reflecting for making sense of the activities (Hofstein and Lunetta, 2004). The laboratory activities offered a little or completely ignored the cognitive demand which is essential for complex knowledge constructions (Hofstein and Lunetta, 2004; Abrahams and Millar, 2008; Abrahams and Reiss, 2012). The heavy emphasis of the laboratory activities on manipulating physical objects, less focusing on assisting the students connecting experimental data with scientific ideas, required that the teachers include high learning demand activities to incorporate explicit strategies for generating the link (Abrahams and Millar, 2008) for knowledge construction. This indicates that laboratory activities are the viable platform for integrating the four STEM disciplines, as STEM integrations warrant cognitive challenge in seeking ways to use the knowledge from the four STEM disciplines to solve real-world problems.
Laboratory activities are instrumental in students understanding electrolysis. The erosions of electrodes, accumulation of deposits at the electrodes, and the changing colors of the electrolytes noticed through the activities are associated with the movement of electrons and chemical changes during electrolysis (Hawkins and Phelps, 2013; Supasorn, 2015). The current electrolysis laboratory activities place emphasis on handling equipment and manipulating physical objects to successfully see the changes as reported in theory (Ahtee et al., 2002; Kamata and Yajima, 2013; Davis et al., 2015). The laboratory activities have limited potential for guiding knowledge construction as the relatively low learning demand activities generated a lower degree of cognitive challenge. The low learning demand activities explain the poor understanding of electrolysis among the secondary level students (Sia et al., 2012; Loh et al., 2014; Ghani et al., 2017).
Integrated STEM-lab, when used in the teaching and learning of electrolysis, allows learning the fundamental scientific and mathematical knowledge from handling and manipulating physical objects. The link between the fundamental knowledge and scientific ideas was established when the knowledge (science and mathematics) guided the exploration of technology in engineering designing and thinking in resolving electrolysis related real-world problems. In other words, high learning demand Integrated STEM-lab activities shaped a greater cognitive challenge in linking observations to scientific ideas. Hence, Integrated STEM-lab activities that consolidate both transdisciplinary integration of the four STEM disciplines and the six elements of the “Framework for STEM Integration in the Classroom” were employed to enhance secondary school students’ understanding about electrolysis.
Besides incorporating the four disciplines, an increasing level of boundary crossings resulting from the greater interconnection and interdependence among the disciplines is the primary feature of Integrated STEM (English, 2016). Different degrees of boundary crossings among the four disciplines result in different forms of integration, with the disciplinary form of integration denoting the lowest form of integration in which the concepts are learned separately in each discipline. The multidisciplinary form of integration signifies that learning the concepts that form the common theme between the two disciplines is the second level of interaction. Learning closely linked concepts to deepen the knowledge is the interdisciplinary form of integration, which is the third level of integration, and applying the knowledge and skills from two or more disciplines to real-world problems to shape the learning is the highest form of integration known as transdisciplinary integration (Vasquez et al., 2013). One of the major concerns in integrating the four disciplines is the unequal representations of the disciplines in STEM education. Predominately, the science and mathematics disciplines form the larger representations, in middle schools the engineering dimension is ignored and most of the time the engineering dimension overshadows the technology dimension (English, 2016, 2017).
Moore et al. (2016) proposed the “Framework for STEM Integration in the Classroom” with six elements as a guide towards performing STEM integration. The first element implies that the integration of the four disciplines should motivate students to engage in learning for the learning to be personally meaningful. The second element postulates that the integration should encourage exploring the technology to participate in engineering thinking and designing in solving real-world problems. The third element specifies that the integration should allow students to learn from failure and engage in redesigning to inculcate engineering thinking skills. The fourth element indicates that the integration should occur in the standard science and mathematics curriculum. The fifth and sixth elements denote that the interaction should be taught in a student-centered manner and emphasize teamwork and communication skills (Moore et al., 2016).
Laboratory activities constitute an integral part of teaching and learning that forms the core component of the secondary school chemistry curriculum (Hofstein and Mamlok-Naaman, 2007). The effectiveness of laboratory activities for knowledge construction is highly dependent on the potential of the activities in linking laboratory learning to real-world applications (Hofstein and Lunetta, 2004). Integrated STEM-lab activities introduced in this study that echo the amalgamation of the transdisciplinary form of interaction due to the boundary crossings of the four STEM disciplines with the six elements of the “Framework for STEM Integration in the Classroom” have the potential to link laboratory learning to real-world applications.
The construction of scientific knowledge is a complex process. As such, merely manipulating physical objects during laboratory activities does not have the potential to support complex knowledge construction as the students are not given time and opportunities for integration and reflections to make meaning of the inquiry (Hofstein and Lunetta, 2004). The authors further said that laboratory activities that engage students in solving authentic problems embark them on interacting and reflecting on the knowledge to solve the problems. The collaborative and cooperative laboratory learning environment that emerged from interacting and reflecting has the potential to support knowledge construction (Hofstein and Lunetta, 2004).
Another proponent of laboratory work advocated that science laboratory work in teaching and learning science effectively enhanced students’ abilities to handle physical materials and students were found to be less effective in associating experimental data to scientific ideas (Abrahams and Millar, 2008). Knowledge constructions are not possible if the students simply observe the changes and remember the process. On the other hand, activities requiring students linking data to scientific ideas create cognitive challenges that support knowledge construction. Cognitive challenges are notable in high learning demand activities in which the strategies to develop the link are explicitly incorporated within the activities (Abrahams and Millar, 2008).
Another study revealed that laboratory activities should be more ‘hands-on’ and ‘minds-on’ for effectively developing primary or secondary students’ conceptual understanding (Abrahams and Reiss, 2012). Practical lessons should have equal representations of ‘doing’ and ‘learning’ for allowing students to use ideas associated with the phenomena rather than seeing the phenomena (Abrahams, 2011). Hands-on denotes the manipulation of physical objects and minds-on implies thinking to relate observations to real scientific ideas.
The greater emphasis on the technical aspects of handling objects and limited opportunities for collaboratively participating in integrating and reflecting on connecting observations with scientific ideas contributed to the claim that laboratory activities are less effective in supporting conceptual understanding. Consolidation of the boundary crossings of the four STEM disciplines with the six elements of the “Framework for STEM Integration in the Classroom” in laboratory activities (Integrated STEM-lab) entails connecting observations and scientific ideas, and advances ‘hands-on’ learning in manipulating physical objects and ‘minds-on’ learning in solving real-world problems. Integrated STEM-lab, which constitutes both the transdisciplinary form of integration due to the crossings of boundaries between the four STEM disciplines and the six elements of framework for STEM Integration, produces a complex learning environment that contributes to knowledge construction (Hofstein and Lunetta, 2004) as the activities collaboratively engage students in reflecting and making sense of the inquiry. Integrated STEM-lab displays a high learning demand with greater cognitive challenges for knowledge constructions (Abrahams and Millar, 2008) as the activities necessitate linking observations to scientific ideas in solving problems.
Teaching and learning electrolysis in chemistry are highly associated with laboratory activities. Electrolysis involves understanding the movement of electrons from the cathode received by the positively charged ions in the electrolyte to form an element or a molecule. The negatively charged ions from the electrolyte travel to the anode and donate electrons and transform into an element or molecule. The processes in the electrolysis are not visible to human eyes. The processes are best visualized through laboratory activities (Ahtee et al., 2002; Kamata and Yajima, 2013; Davis et al., 2015). The notion that electrolysis is one of the electrochemical processes utilized widely in industries in manufacturing processes (Nagel et al., 2019) by merely observing chemical changes in laboratory activities is inadequate to support the complex conceptual understanding of electrolysis. For constructing knowledge on electrolysis, the activities should trigger cognitive challenges associating observations to real-world applications in a meaningful way. The cognitive challenge which is essential for knowledge construction, evident in the high learning demand Integrated STEM-lab activities, suggests that Integrated STEM-lab is an appropriate strategy for understanding electrolysis.
Ahtee et al. (2002) asserted that electrolysis is detected through color transformation or bubble formation. As such, learning from observing and visualizing the changes for real using laboratory activities is the best possible way to learn about electrolysis. For instance, laboratory work was performed using bismuth as the anode and cathode by connecting both the electrodes to the power supply in the presence of sodium hydroxide as electrolyte solution (Nagel et al., 2019). Electrolysis of water is visualized through a microfluidic device in a laboratory setting (Davis et al., 2015). Microscale electrolysis of coin-type lithium batteries and filter paper was viewed as useful to understand the associated scientific concepts and encouraged their interest in learning electrolysis (Kamata and Yajima, 2013). Electrolysis of water using solar energy which resulted in building a hybrid car model was used in understanding electrolysis (Zhe et al., 2010). These laboratory works were designed in such a way that they prompt students to follow a recipe like rhetorical procedures. The thinking, evaluating and analyzing skills which are imperative in learning about electrolysis were ignored in designing laboratory work on electrolysis. The low learning demand laboratory work exhibited little evidence of cognitive challenge linking findings and observations to an authentic real-world application. The lacking in laboratory work warrants limited support for complex knowledge construction. The high learning demand Integrated STEM-lab activities designed by the merging of the transdisciplinary form of interaction from the increasing level of boundary crossings between the four STEM disciplines and the six elements of the “Framework for STEM Integration in the Classroom” advance cognitive challenge linking observations to real scientific ideas, offering greater possibility for knowledge construction in electrolysis. Hence, this study was conducted to seek an answer to the research question “What is the effect of Integrated STEM-lab activities in improving students’ understanding of electrolysis?”
Pre-test | Treatment | Post-test |
---|---|---|
Students completed an electrolysis diagnostic instrument with 17 items | Integrated STEM lab activities were used to teach electrolysis | Students completed an electrolysis diagnostic instrument with 17 items |
Qualitative interviews |
A pre-test Electrolysis Diagnostic Instrument (EDI) with 17 items was administered prior to the treatment. The pre-test was followed by the treatment using Integrated STEM-lab activities. After completing the treatment, a post-test was administered, and the interview was conducted. The same instrument was employed for both pre- and post-tests.
No. | Interview questions | Concept |
---|---|---|
1 | What do you understand about electrolytes? | Electrolytes and non-electrolytes |
Give two examples of electrolytes that you know. | ||
2 | In the electrolysis of 0.5 M copper(II) nitrate solution using a carbon electrode, name the ions attracted to the anode | Electrolysis of aqueous solutions |
Which ion will be discharged? | ||
Explain your answer | ||
3 | Explain how to electroplate an iron key with silver. In answering this question refer to the experiment on Integrated STEM-lab that you have performed | Electrolysis in industry |
The interview questions were provided to the teachers to validate the appropriateness of the questions in measuring students’ understanding of the three concepts. The teachers suggested a few amendments such as ‘includ[ing] statements like referring to the STEM-lab in answering’ to avoid students from providing general answers. For the STEM-lab activities, the teachers suggested using readily available substances that students frequently used to encourage participation of the students. The teachers also suggested presenting more relevant real-world contexts that match the students’ level to ensure participation in thinking and designing processes.
Week | Treatment |
---|---|
1 | Pre-test: IDE |
2 | Activity 1 (electrolytes) and Activity 2 (electrolysis of molten substances) |
3 | Activity 3 (electrolysis of aqueous solutions) and Activity 4 (electroplating of metal) |
4 | Activity 5 (metal purification) |
5 | Post-test: IDE and interview |
The five Integrated STEM-lab activities exhibited a transdisciplinary form of integration. The highest level of integration is executed in the activities because real-world contexts provided a platform for the crossings of the boundary between all four disciplines of STEM (Vasquez et al., 2013). During the activities, in the process of seeking solutions to real-world problems, the students consistently moved between the disciplines. The activities started with the students learning fundamental science and mathematics knowledge. The real-world problems posted in the activities required them to participate in engineering thinking and designing. The basic knowledge of science and mathematics guided the students in engineering/reengineering their thoughts in designing solutions. While participating in engineering thinking and designing, the students explored the technology to be used in the engineering thinking and designing process. For instance, in activity 1 students learned the science concepts differentiating between electrolytes and non-electrolytes, the properties of electrolytes as ionic compounds and free moving ionic compounds result in electrical conductivity. Learning about electrolytes denotes the science dimension. The scientific knowledge was used to solve the engineering problem on inventing natural isotonic drinks. Engineering thinking and design was used in relating the ammeter readings to propose the possible combinations of fruit and vegetable juices that result in the best isotonic drinks. Associating the ammeter reading with the masses of fruits and vegetables to decide on the ratio for mixing the juices denotes the mathematics dimension. Exploring the technology in deciding the packaging of the isotonic drink signifies the technology dimension. The details about the four STEM disciplines in the five STEM-lab activities are provided in Appendix 1, ESI†.
The crossing of boundaries not necessarily follows the order of science, technology, engineering, and mathematics. In contrast, the crossing of boundaries between the disciplines was materialized when the six elements constituting the “Framework for STEM Integration in the Classroom” (Moore et al., 2016) were embraced. The framework requires that the Integrated STEM activities (1) include a motivating and engaging environment for the learning to be personally meaningful, (2) include exploration of technology in engineering thinking and designing using the fundamental knowledge of science and mathematics as a problem-solving strategy, (3) allow participating in engineering thinking through learning from failure to redesign based on what they have learned, (4) be infused into the standard science and mathematics curriculum, (5) be taught in a student-centered manner, and (6) promote collaborative and communicative skills.
The six elements and the crossing of the boundaries between the four STEM disciplines expressed when the five activities were conducted in three stages (learning the concepts, experimenting the concepts and applying the concepts to real-world contexts). In the first stage, the students were introduced to the scientific concepts and mathematical applications inherent to the aims of the activity. In the second stage, the students performed an experiment investigating the concepts. In the third stage, the understanding gained from the first and second stages was applied to a real-world issue, whereby in the third stage the students engaged in engineering thinking, and explored available technologies to develop engineering design with the application of science and mathematics in the context of the given real-world issues.
In stage one of activity 1, the teacher posed questions such as ‘What do you know about electrolytes?’, ‘Why electrolytes are needed and how are they useful in daily life?’, and ‘Give five examples of electrolytes’ to retrieve the students’ prior knowledge on electrolytes which they have learned in previous years. The students in groups collaboratively discussed with the teacher the answers to these questions. The students were provided with substances such as sugar cubes, salt, lemon juice, vinegar, and isotonic drinks available in the market and apparatus such as copper wires, multimeters and crocodile clips. The students used the apparatus and experimented the substances to group them as electrolytes and non-electrolytes. The students in groups discussed the findings, exchanged ideas and reached a consensus. The learning environment appeared to be personally meaningful as they worked in a team communicating the findings. In stage 2, a wider range of substances from fruit and vegetable juices (coconut water, and orange, apple, celery, carrot, and lemon juices) to chemicals such molten lead(II) nitrate and copper(II) sulphate solutions was provided. The students designed an experiment to investigate the behaviors of the substances and identified the best electrolyte based on the current produced. In deciding on the experiment, the students had made several attempts and the first few trials were not successful. They discussed where and why the planning went wrong and finally after a few rounds of discussion a correct experimental procedure was prepared. In each attempt to produce a good mixture of the juices the students related the ammeter readings to the masses of the fruits and vegetables and the volume of water. Learning from failure in designing and redesigning is claimed as a hallmark of engineering thinking (Moore et al., 2016).
Once the electrolyte to be commercialized as an isotonic drink was identified, in stage 3 the students engaged in exploring technologies to design the packaging for the isotonic drink. At this point again, the students communicated and shared their ideas in thinking/rethinking of the design. The students worked in groups and made many attempts towards engineering and reengineering the packaging of the drink. The science and mathematics knowledge inherent to electrolysis which comprises the standard learning objectives of the lessons was investigated in depth in producing the drink. In other words, the Integrated STEM-lab activities do not add on to the current objectives. Instead, the integration resulted in enhancing the teaching and learning of the content in which their increasing interconnectedness and interdisciplinary nature was reflected.
The remaining activities were also executed similarly in three stages. In activities 2 and 3, the students investigated the electrolysis of molten and aqueous solutions. At the first stage, the lesson focused on learning about electrolysis. This includes information about cathodes and anodes and identifying suitable electrodes. In stage 2, the knowledge gained from stage 1 was investigated using the given materials and finally in stage 3 the understanding gained from stage 2, and 3 was applied to the real world problem of developing a prototype of a foot therapy machine which functions using electrolysis concepts. In activities 4 and 5, the students learned about the electroplating of metal and purification of metal. In stages 1 and 2 they learned about the application of the electrolytic process in the electroplating and purification of the metal. In stage 3, the students invented a method of using solar energy to perform electroplating using a water purifier. In activities 4 and 5, the students applied the knowledge gained from all five activities to electroplating a nail and designing a water purifier. Activities 4 and 5 reflect on the industrial application of electrolysis.
Code | Category | Concept |
---|---|---|
Explain the meaning of electrolytes | Salt solutions | Electrolytes |
Classify electrolytes and non-electrolytes | Ionic compounds | |
Charged particles | ||
Electrical conductivity | ||
Chemical changes | ||
Describe the electrolysis of molten and aqueous solutions | Movement of ions | Electrolysis of molten and aqueous solutions |
Negatively charged ions attracted to the anode | ||
Positively charged ions attracted to the cathode | ||
Discharging of ions at the electrodes | ||
Positioning in the electrochemical series | ||
Observations at the electrodes | ||
Describe the electroplating and purification of metal | Name the electrolyte and electrodes | Electrolysis in industry (electroplating and purification of metal) |
Name the ions present in the electrolyte | ||
Explain the reaction at the electrodes | ||
Note the chemical changes observed |
For instance, for the question ‘What do you understand about electrolytes?’, Student 1 (S1) responded, “Electrolytes are ionic compounds that conduct electrical current and undergo chemical changes when electrical current flows through [them].” S1's utterances represent the code ‘explain the meaning of electrolytes.’ The underlined phrases in the codes portray the categories that explain the codes for the electrolytes concept. For the question ‘Explain why the bulb is lighted when using copper(II) nitrate 0.5 M as the electrolyte’, S2 said, ‘The aqueous solution contains freely moving ions, the hydroxide ions will be attracted to the cathode and discharged. Copper ions will move to the anode and [be] discharged here’. S2's utterances imply the code describing the electrolysis of the aqueous solution. The underlined phrases show the categories that explain the codes describing the electrolysis of the aqueous solution. For the question ‘Explain how to electroplate iron key with silver”, S4 said, ‘Silver rod should be placed as an anode and the iron key as a cathode. Both electrodes should be placed in a silver nitrate solution. Silver nitrate solution is the electrolyte. The anode erodes because electrons are donated to form silver ions. These ions received electrons from the cathode, discharged and formed silver deposits surrounding the key.’ The underlined phrases in the responses provided by S4 correspond to the code describing the electroplating of metal. The underlined phrases are the categories that explain the code.
Subscale | Test | Mean | Std deviation |
---|---|---|---|
Overall | Pre-test | 6.90 | 3.25 |
Post-test | 10.66 | 2.88 | |
Electrolytes and non-electrolytes | Pre-test | 2.34 | 1.26 |
Post-test | 3.40 | 0.90 | |
Electrolysis of aqueous solutions | Pre-test | 2.22 | 1.53 |
Post-test | 3.62 | 1.32 | |
Electrolysis in industry | Pre-test | 2.34 | 1.33 |
Post-test | 3.64 | 1.34 |
A gain score of 3.76 is demonstrated for the overall performance in the EDI by comparing the pre- and posttest mean scores. For the subscale electrolytes and non-electrolytes, a gain score of 1.06 is notable. Gain scores of 1.40 and 1.30 are documented for the subscales electrolysis of aqueous solutions and electrolysis in industry. One-way multivariate analysis of variance (MANOVA) was performed on the scores to investigate the differences among the subscales further.
Prior to conducting MANOVA, the data were checked for the equality of variance–covariance matrices. Box's M value of 9.24 with a p-value of 0.18 (p > 0.05) indicates that the variance–covariance matrices between the two groups were assumed to be equal. As the assumption was met, one-way MANOVA was performed to investigate whether the differences between the mean scores of the three subscales electrolytes and non-electrolytes, electrolysis of aqueous solutions and electrolysis in industry were significant. The findings (Table 6) revealed that there was a statistically significant mean difference between the pre-test and post-test mean scores combining all three dependent variables (electrolytes and non-electrolytes, electrolysis of aqueous solutions and electrolysis in industry): Wilks’ lambda = 0.67, F(3,96) = 16.16, p < 0.05. The partial eta squared η2 = 0.336 indicates that the treatment explains 33.6% of the differences between the pre- and post-test mean scores for the three subscales explained by the treatment.
Value | F | df | Error df | Sig. | Partial eta squared | |
---|---|---|---|---|---|---|
Pillai's trace | 0.33 | 16.16 | 3.00 | 96.00 | 0.00 | 0.34 |
Wilks’ lambda | 0.66 | 16.16 | 3.00 | 96.00 | 0.00 | 0.34 |
Hotelling's trace | 0.51 | 16.16 | 3.00 | 96.00 | 0.00 | 0.34 |
Roy's largest root | 0.51 | 16.16 | 3.00 | 96.00 | 0.00 | 0.34 |
Following the significant findings obtained from the multivariate test, the univariate main effects were examined by a follow-up ANOVA. Before conducting ANOVA, the assumption of the equality of variances was checked. The results of Levene's test are displayed in Table 7.
Subscale | F | df1 | df2 | Sig. |
---|---|---|---|---|
Electrolytes and non-electrolytes | 13.83 | 1 | 98 | 0.00 |
Electrolysis of aqueous solutions | 6.64 | 1 | 98 | 0.01 |
Electrolysis in industry | 0.22 | 1 | 98 | 0.64 |
The Levene's test findings’ homogeneity of the variance was not violated for the subscale electrolysis in industry (p > 0.05). For the subscales electrolytes and non-electrolytes and electrolysis of aqueous solutions, the homogeneity of the variance was violated (p < 0.05). As such, following Tabachnick and Fidell's (2007) suggestion, a more conservative alpha level was used to interpret the findings. Further to avoid Type 1 error, Bonferroni adjustments were used (αadj = αexp/3 levels). For this purpose, an alpha-level of 0.05 was divided by three (number of dependent variables). The new adjusted alpha is 0.017. The results of the univariate analysis are presented in Table 8.
Subscale | Sum of squares | df | Mean | F | Sig. | Partial eta squared |
---|---|---|---|---|---|---|
Electrolytes and non-electrolytes | 28.09 | 1 | 28.09 | 23.48 | 0.00 | 0.19 |
Electrolysis of aqueous solutions | 54.76 | 1 | 54.76 | 29.00 | 0.00 | 0.23 |
Electrolysis in industry | 42.25 | 1 | 42.25 | 23.70 | 0.00 | 0.20 |
The univariate findings revealed that significant differences were noticed between pre- and post-tests for all three subscales. For the subscale electrolytes and non-electrolytes the pre-test (M = 2.34; SD = 1.26) and post-test (M = 3.40; SD = 0.90) mean scores were significantly different (F(1,98) = 23.48; p < 0.0013). A partial eta squared of 0.19 indicates that the treatment causes 19% of the variances. The differences identified between the pre-test (M = 2.22; SD = 1.53) and post-test (M = 3.62; SD = 1.32) mean scores of the electrolysis of aqueous solution also appeared significant (F(1,98) = 28.99; p < 0.0013). A partial eta squared of 0.23 reflects that 23% of the differences are due to the treatment. A partial eta squared of 0.19 indicates that the treatment contributes 19% of the variances in the differences between the pre-test (M = 2.34; SD = 1.33) and post-test (M = 3.64; SD = 1.34) mean scores for the subscale electrolysis in industry, which appeared significant (F(1,98) = 23.69; p < 0.0013).
When the interviewer probed further and asked the students to reflect on experiments that they had conducted, the responses appeared to be scientifically explained whereby the students connected electrolytes with electrical conducting and chemical changes. Some just said, ‘electrolyte solutions conduct electricity’, and they were unable to explain why the solutions conduct electricity. One student said, ‘the ions in electrolytes cause the current flow.’ Another student with a slightly deeper understanding stated, ‘the current flow happens because the ions in electrolytes are moving freely.’ The students found that electrical conductivity has got something to do with ions in the electrolytes. The researcher provoked the students asking, ‘what about the chemical changes?’ The excerpts ‘the ions in the electrolyte solutions were separated and discharged because the color of electrolytes changed after some time.’ Reflecting on the same idea, another student said, ‘chemical changes happened because I could see the color of electrolytes changes’. In sum, from the responses provided, it could be postulated that a few students had acquired the understanding that electrolytes contain ions that undergo chemical changes and also conduct electricity. However, some stated examples of electrolytes without providing the details, exhibiting surface level understanding.
In explaining the electrolysis process, notably, the responses constitute common themes such as positively charged ions in the electrolyte attracted to the cathode and negatively charged ions attracted to the anode, discharging of the ions at the electrodes releases gases, copper deposits and positioning of the ions in the electrochemical series. The themes are demonstrated in vignettes ‘ion nitrate will be at the anode, and copper ion will be moving towards cathode’ and ‘nitrate and hydroxide ions will be moving closer to the anode and copper and hydrogen moves to the cathode.’ The interviewer further probed asking where the hydroxide and hydrogen ions were found. One student responded saying, ‘from the aqueous solution. The aqueous solution contains water. Water exists as hydrogen and hydroxide ions’. The researcher continued asking, ‘What will be observed at the anode and cathode?’ There were many mixed answers such as ‘copper metal will be there’, ‘maybe copper because there are no other positively charged ions except copper’, ‘nitrogen gas will be released’ and ‘oxygen gas will be released at the anode, and at the cathode deposits of copper metal can be seen’. The excerpts above suggest that the students acquired the understanding that the ions in the electrolyte moved and discharged at the electrodes. However, confusion was noticed in illustrating the observation. This is commensurate with the observation that they were unsure which ions will be discharged. In the researcher's attempt probing further one student said that ‘ions positioned at the lower level of electrochemical series easily discharged than the top ones’.
The next question assessed how the knowledge on the electrolytic process mentioned earlier was used in the industrial application in explaining the electroplating of a silver key. The understanding was reflected in the ability of the students employing common phrases such as identifying the suitable electrolyte, electrodes, the ions present in the electrolyte, reactions at the electrodes and the observation. A majority of the students were able to provide partially correct answers. Most of them indicated silver nitrate as an electrolyte, and the silver metal is the anode, and the silver key is fixed as a cathode. A total of five students illustrated the presence of Ag+ ions, NO3− ions, H+ ions, and OH− ions, and the negative ions are attracted to the anode and the positive ions to the cathode. However, only three students indicated that at the cathode silver ions will be discharged, and the anode will erode and release silver ions into the solution. At the cathode, the silver metal will be deposited around the key. The remaining students pointed out that OH− will be discharged at the cathode as such oxygen will be released at the cathode. At the anode, H+ will be discharged and produces hydrogen gas.
In summary, the categories and phrases used by the students in expressing the understanding show that only a few students acquired a complete understanding of electrolytes, the electrolytic process, and the application of the process in industry. The findings reveal that the majority of the students partially comprehended the knowledge on electrolysis and its industrial application although they knew what electrolytes are. The students used specific examples from the activities to reason their answers. This implies that the activities are instrumental in understanding electrolysis. For instance, coconut water was illustrated as an isotonic drink that possibly could replace commercial drinks available in the market.
The qualitative interview findings allowed the researchers to obtain insights into the quantitative outcome. The common phrases used in explaining the answers depict that the students comprehended the knowledge on electrolysis well. However, not all the students included the entire phrases that reveal that they acquired complete understanding. A majority of them exhibited partial understanding. In responding to the interview questions, the students frequently had referred to the curriculum on Integrated STEM-lab. For instance, the students referred to the ammeter readings from the electrolysis of coconut water and defended that coconut is a better isotonic drink than commercially available drinks. Referring to activities in answering the questions provides insights into the effect of the Integrated STEM-lab activities. Perhaps, upon prolonging exposure to the curriculum, more students would be able to express a complete understanding of the concept. It is evident from the study performed by Park et al. (2018) that young children progressively construct understanding while they engage in engineering practices in STEM education.
The amalgamation of the transdisciplinary form of integration due to the boundary crossings between the four disciplines of STEM with the six elements of the integrated STEM framework explains the effectiveness of the Integrated STEM-lab activities in enhancing understanding on electrolysis. In doing the activities, the teacher guided the students in learning the fundamental electrolysis concepts. The students designed experiments to test the concepts and later used the understanding of the fundamentals (electrolysis and calculations), and observations from the experiments in designing (redesigning) in improving real world problems. The technology application was explored throughout the designing and redesigning actions. In this context, the learning appears to be meaningful to the students as the learners engaged in thinking and rethinking of using science and mathematics knowledge in engineering applications to the expanse of the technology. The activities allowed learning the fundamentals (electrolysis) and understanding the applications in industry as well as in everyday events. Throughout the activities, the students collaboratively involved in executing the learning. The cognitive challenge was demonstrated on many occasions throughout the activities. The cognitive ability was tested by designing the experiment at the initial stage to the later stage of exploring technology in engineering thinking and designing to solve the problem. At all these points, the students involved in serious discussions and executed their actions. They learned from failure and repeated the actions until the problem was solved. The activities exhibited high learning demand as the activities compelled the students to reflect and connect observations to real-world applications. The high learning demand activities with an increase in cognitive challenge allow knowledge construction (Hofstein and Lunetta, 2004; Abrahams and Millar, 2008; Abrahams and Reiss, 2012).
The findings of this study correspond to some other studies which have documented positive effects of employing STEM education across cognitive and affective measures. Young children's understanding and application of volume through the practices of engineering design in STEM activities were explored (Park et al., 2018). The case study revealed that students understood the concept progressively when they engaged in structuring the volume in engineering design. In a different study, STEM education integrated with problem-based learning in stoichiometry lessons resulted in improving grade 11 students’ analytical thinking abilities and attitude toward science (Chonkaew et al., 2016). STEM learning through engineering design impacted middle secondary students’ interest in STEM (Mohd Shahali et al., 2017). Students who were taught using STEM project-based learning exhibited improved science achievement (Erdogan et al., 2016). High school students developed positive perceptions on STEM with the implementation of STEM integrated robotics (Chen and Chang, 2018). The STEM approaches used in the abovementioned interventions seem to highlight one component of STEM. In engineering-design based initiatives, the engineering component plays the central role. In robotic integrated STEM lessons the technology component is emphasized. Integrated STEM-lab proposed in this study is an example of an integrated STEM approach that projects balanced integration of the four STEM disciplines.
One of the five issues that contribute to the complexity and challenges in advancing STEM education is promoting equitable discipline representations (English, 2016, 2017). The notion engineering dimension is often neglected in the primary and middle school curriculums (English and King, 2015) and engineering is a platform for merging the science, technology, and mathematics as engineering does not exist in isolation, the engineering dimension frequently gains greater recognition in STEM approaches (Katehi et al., 2009). In later years, when computing is perceived inseparable from science and mathematics, computation and computational thinking are acknowledged as a core practice in science and mathematics (Weintrop et al., 2016), technology dramatically overshadows the engineering dimension. One discipline tends to override the other. Additionally, the disciplinary context frequently ignored when the focus is lamented in following procedures in solving problems or engaging in projects (English and King, 2018). The Integrated STEM-lab introduced in this study is a possible solution to address the difficulty in maintaining the integrity of disciplines in integrated STEM activities.
Additionally, Integrated STEM-lab coincides with the perspective of integrated STEM in enhancing the existing curriculum instead of adding to the curriculum (Bryan et al., 2015). The Integrated STEM-lab activities prompt the students to collaboratively involve and communicate their ideas in using engineering design supported by the use of technology in solving real-world issues. The real world problems on the three subscales of the electrolysis topic were infused into the existing laboratory practice. Hence, this results in enhancing the existing curriculum by allowing the students to learn electrolysis integrated with the engineering, mathematics and technology disciplines.
In conclusion, this study endorses that STEM pedagogies are effective in boarding the conceptual understanding as found from the findings of other STEM studies. The findings of this study provide evidence that the Integrated STEM-lab activities are minds-on activities that embrace the nature of meaningful learning as minds-on meaningful learning is the best means to learn about electrolysis (Sia et al., 2012; Benue and Angura, 2017). The findings of the study inform the teachers on using an alternative, integrative STEM lab pedagogy to teach electrolysis and subsequently address the claim teachers lacking STEM education related pedagogical knowledge (Nadelson et al., 2013; Radloff and Guzey, 2016; Ahmad Zamri, 2017). STEM education is one of the key national educational reform agendas, and Integrated STEM-lab activities are resourceful to curriculum developers and policymakers. The activities are expected to serve as guides in professional development sessions for teachers.
The activities serve as an example for STEM educators around the world. Notably, in Malaysia, the country where this study was performed, STEM integration is one of the nation's primary agendas, and the country is progressing with the introduction of various STEM initiatives through school curricula (BPK, 2016). In the Malaysian context, having STEM integration outside formal education is the greatest challenge. Malaysia practices an exam-oriented centralized education system governed by the Ministry of Education. The education system prepares students for the secondary school leaving examination, which the students will be sitting at the end of the secondary education. The teaching and learning processes closely follow the curriculum specification from the Ministry to ensure that the students were taught all the concepts assessed in the examination. On this account, STEM initiatives outside the curriculum context are frequently less attractive to educators. As such, a viable means to have STEM integration in a structured education system is through integrating STEM into the existing curriculum as Integrated STEM as suggested in this study.
Footnote |
† Electronic supplementary information (ESI) available. See DOI: 10.1039/c9rp00021f |
This journal is © The Royal Society of Chemistry 2019 |