Improving Chemistry Concept Understanding through QuizWhizzer-Assisted

Study Case Improving Chemistry Concept Understanding through QuizWhizzer-Assisted Problem-Based Learning on Buffer Solution Material Michael Kurniawan (2018123456) University of Cincinnati, 2600 Clifton Ave, Cincinnati, OH 45221, United States kurniaml@mail.uc.edu Abstract Chemistry material, especially regarding buffer solutions, involves many abstract concepts that require gradual and in-depth understanding. Therefore, the ability to understand concepts is a crucial element in the learning process. This study aims to analyze the extent to which the application of problem-based learning (PBL) supported by QuizWhizzer can improve the conceptual understanding of 11th grade students at Cincinnati Laboratory High School on the topic of buffer solutions. This study uses a quantitative approach with a quasi-experimental method and a nonequivalent control group design. The sample was obtained using cluster random sampling, resulting in an experimental class that received problem-based learning with QuizWhizzer support and a control class that only used problem-based learning. Data were collected through observation, written tests (pre-test and post-test), and documentation. The questions were tested through validity, reliability, difficulty level, and discrimination analysis using Rasch Model Analysis. The hypothesis test results showed a significance value of less than 0.05. The N-Gain value showed a higher increase in concept understanding in the experimental class (0.67) compared to the control class (0.56). The conclusion of this study states that the application of QuizWhizzer-assisted problem-based learning significantly improves students' understanding of the concept of buffer solutions. Keywords: problem-based learning, QuizWhizzer, conceptual understanding. MICHAEL KURNIAWAN 1 Study Case INTRODUCTION In chemistry, particularly in the subject of buffer solutions, there are various abstract concepts that are often challenging for students to understand in depth [1][2]. Understanding these abstract concepts requires a gradual and in-depth process, unlike concrete concepts [3]. As a result, many students experience difficulties when studying buffer solutions, such as identifying conjugate acid-base pairs, understanding the working principles of buffer systems, and performing accurate pH calculations. Chemistry teachers at the University of Cincinnati Laboratory High School reported that most 11th grade students still had difficulty understanding these aspects. Similar difficulties were also found in previous studies, such as the inability to classify buffer components [4], weak mastery of the concepts of chemical equilibrium and reaction shifts [5], and mathematical difficulties in calculating molarity and pH values [1]. These obstacles can interfere with the learning process of more complex chemistry concepts if not addressed with an effective learning approach. Conceptual understanding is the ability to recognize conceptual relationships between ideas and apply them in problem solving [6]. Improved conceptual understanding can be achieved through the application of appropriate learning models and actively involving students in the learning process. Student activity during learning greatly affects their success in understanding the material [7]. In the context of chemistry learning, students can be considered successful if they are able to master concepts thoroughly and apply them in solving scientific problems [8]. One effective approach is Problem-Based Learning (PBL), a learning model that emphasizes contextual problem solving to encourage deep conceptual understanding [9]. Through PBL, students are invited to identify problems, develop hypotheses, and integrate new knowledge to find solutions. Previous studies have shown that PBL has the potential to improve critical thinking, problem solving, and scientific concept comprehension [10]. The effectiveness of the PBL model has been supported by a number of studies, including by Anderson et al. [11], who found a positive relationship between critical thinking skills and conceptual understanding after the implementation of problem-based learning. Another study by Johnson & Lee [12] also showed that PBL can improve critical thinking skills and conceptual understanding in chemistry topics, including buffer solutions. MICHAEL KURNIAWAN 2 Study Case In addition to learning models, the use of interactive media also plays an important role in improving student understanding. Educational game-based learning media can create a fun learning atmosphere and motivate students to actively participate [13][14]. Learning accompanied by interactive elements has been proven to increase cognitive engagement and strengthen conceptual memory [15]. One interactive media that is widely used is QuizWhizzer, an education-based game platform that combines interactivity, competition, and collaboration among students. QuizWhizzer encourages active student engagement, stimulates critical thinking skills, and strengthens understanding of scientific concepts through game-based exercises [16][17]. In addition, this medium has also been shown to increase student motivation and learning outcomes [18][19]. However, to date, there has been little research examining the use of QuizWhizzer in the context of chemistry learning at the secondary school level. Therefore, this study was conducted to analyze the effectiveness of implementing a problem-based learning model assisted by QuizWhizzer media in improving students' conceptual understanding of buffer solutions in the United States educational environment. METHOD This study was a quantitative study with a quasi-experimental approach using a nonequivalent control group design. The research sample consisted of two classes of 11th grade students at the University of Cincinnati Laboratory High School, namely 11th grade Science 5 as the experimental class and 11th grade Science 3 as the control class, with a total of 71 students. Sampling was conducted through cluster random sampling. The experimental class received treatment in the form of the application of Problem-Based Learning (PBL) assisted by the QuizWhizzer media, while the control class only received a problem-based learning model without additional media. Research data were collected through classroom observation, written tests (pre-test and post-test), and supporting documentation. The test instrument consisted of 19 two-tier multiplechoice questions, where the second level used the Certainty of Responses Index (CRI) to measure the level of students' confidence in their answers. All questions were tested using Rasch Model Analysis to ensure the validity, reliability, difficulty level, and discriminating power of the questions before they were MICHAEL KURNIAWAN 3 Study Case used in the study. The data were analyzed using normality and homogeneity tests, hypothesis testing (t-test), N-Gain testing, and analysis of students' concept understanding profiles. The normality and homogeneity tests showed that the data were normally distributed and homogeneous, so the testing continued with parametric tests. Two types of t-tests were used, namely the paired sample t-test to measure changes in each group, and the independent sample t-test to compare results between groups. RESULTS AND DISCUSSION This study analyzes the effectiveness of implementing a media-assisted problembased learning model using QuizWhizzer in improving students' conceptual understanding of the topic of buffer solutions. Hypothesis Testing A paired sample t-test was used to determine whether there was a significant difference between the pre-test and post-test scores in each group. • For the experimental class that received problem-based learning assisted by QuizWhizzer, a Significance (2-tailed) value of 0.000 < 0.05 was obtained, indicating a significant increase in students' conceptual understanding. • For the control class that only used problem-based learning, the test results showed a Significance (2-tailed) value of 0.000 < 0.05, which means that there was a significant increase even without the use of interactive media. Furthermore, an independent sample t-test was used to compare the effectiveness of the two treatments. The test results showed a Significance (2-tailed) value of 0.005 < 0.05, indicating that there was a significant difference between the post-test scores of the two groups. Thus, it can be concluded that QuizWhizzer-assisted problem-based learning is significantly more effective in improving students' conceptual understanding than conventional problem-based learning. N-Gain Score Test To assess the increase in conceptual understanding quantitatively, the N-Gain Score was used, which was calculated based on the comparison between the increase in posttest and pre-test scores to the maximum score. The N-Gain value for the experimental class was 0.67, while for the control class it was 0.56. Based on the learning effectiveness category, both were in the moderate MICHAEL KURNIAWAN 4 Study Case category, but the experimental class showed a higher increase. This indicates that the integration of QuizWhizzer in the PBL model contributed to a better increase in conceptual understanding. Table 1. N-Gain Score Test Results Analysis of Student Conceptual Understanding The main objective of this study was to identify and analyze the improvement in students' conceptual understanding of buffer solutions after the implementation of QuizWhizzer-assisted problem-based learning. The assessment instruments consisted of pre-tests and post-tests equipped with the Certainty of Responses Index (CRI) indicator. CRI was used to assess the level of students' confidence in their answers, with a scale of 0 to 5: • 0: Completely guessing • 1: Partially guessing • 2: Not sure • 3: Sure • 4: Almost sure • 5: Very sure [20] A low CRI score indicates that students answered without sufficient confidence, indicating weak conceptual understanding or random guessing. Conversely, a high CRI score indicates greater confidence and conceptual understanding. If students answer correctly with a high CRI, it can be concluded that they understand the concept well. However, if students answer incorrectly with a high CRI, it indicates a misconception that needs to be corrected. Descriptive statistical analysis shows that the average pre-test score for the experimental class was 35.82, while for the control class it was 32.33, indicating that their initial abilities were almost similar. After the treatment, the post-test scores increased to 79.09 for the experimental class and 70.52 for the control class. This increase confirms that both conventional problem-based learning and interactive mediaassisted learning are equally effective, but the use of QuizWhizzer provides more MICHAEL KURNIAWAN 5 Study Case significant results. Figure 1. Percentage of Increase in Student Conceptual Understanding Based on Indicators Based on the indicator analysis results, the highest increase in the experimental class occurred in the “exemplifying” indicator at 59.7%, while in the control class, the highest increase was in the “comparing” indicator at 55.8%. Further analysis using CRI also showed differences in confidence levels between the two classes. The experimental class showed a significant increase in the “very confident” category, while the control class showed a more moderate increase. Figure 2. Percentage of Student Conceptual Understanding Categories Figure 2 shows a significant increase in the “understands concept” category in the experimental class, from 17.3% to 73.2%, an increase of 55.9%. Conversely, the “does not understand concept” category decreased from 53.1% to 10.4%, a decrease of 42.7%. A similar pattern was also found in the control class, where the “understands concept” category increased from 10.7% (pre-test) to 59.4% (post-test), an increase of 48.7%. Meanwhile, the “does not understand concept” category decreased from 68.3% to 20.3%, a decrease of 48.0%. MICHAEL KURNIAWAN 6 Study Case The high percentage in the “does not understand concept” category in the pre-test stage in both classes was due to the absence of formal teaching on the topic of buffer solutions prior to the treatment. However, after learning took place, both with and without the QuizWhizzer media, there was a significant decrease in this category, indicating an increase in students' conceptual understanding. Figure 3. Percentage of Conceptual Understanding Categories Based on Indicators in the Experimental Class Figure 3 shows that the highest “understands concept” category in the experimental class was in the ‘exemplifying’ indicator with a percentage of 95.8%, while the lowest was in the “explaining” indicator with a percentage of 63.9%. Figure 4. Percentage of Conceptual Understanding Categories Based on Indicators in the Control Class MICHAEL KURNIAWAN 7 Study Case Conversely, Figure 4 shows that the control class obtained the highest percentage on the “inferring” indicator at 88.6%, and the lowest on the “explaining” indicator at 32.4%. The “exemplifying” indicator was measured through questions 18 and 19, which were related to the role of buffer solutions in everyday life. The high scores on this indicator were due to the use of Learning Activity Sheets (LAS) containing concrete examples of the function of buffers, such as the application of buffer solutions in human blood and the pharmaceutical industry. The Problem-Based Learning (PBL) approach also reinforced this because each phase of learning began with a real-world contextual problem, which helped students build conceptual understanding independently. Conversely, the “explaining” indicator is measured through questions 8, 9, and 11, which focus on the working principles of buffer systems. Low scores on this indicator are due to the difficulty level of the questions, which are categorized as difficult to very difficult based on item measure analysis. To answer these questions correctly, students need to understand the relationship between the concepts of chemical equilibrium and Le Chatelier's Principle, as also found in the study by Marsita et al. [5], that the concepts of chemical equilibrium and reaction shifts are often a major source of difficulty for students. Therefore, a stronger conceptual emphasis is needed during the learning process so that students do not experience misconceptions in this section. Meanwhile, the “inferring” indicator, represented by question number 1 regarding the definition of a buffer solution, had a low level of difficulty (very easy), so most students answered correctly. This explains why the highest percentage of the “understands concept” category in the control class appeared in this indicator. Classroom Observation and Qualitative Analysis During the learning process, the experimental class (XI Science 5) showed higher enthusiasm and participation compared to the control class (XI Science 3). In the discussion session and QuizWhizzer activity, students showed healthy competition to get the top position on the game scoreboard. This competitive spirit fostered intrinsic motivation among students, which directly had a positive impact on their cognitive and social engagement during learning. Internal factors such as curiosity and learning motivation played an important role in the success of the learning process. Students with a high level of curiosity tended to be more active in exploring concepts and seeking in-depth understanding. The use of QuizWhizzer has proven effective in helping students understand MICHAEL KURNIAWAN 8 Study Case abstract chemistry material. These findings are in line with the results of studies by Kharolinasari et al. [13] and Yustiqvar et al. [14], which state that interactive learning media can create a fun learning atmosphere, increase student engagement, and strengthen conceptual understanding. QuizWhizzer, with its competitive system and direct feedback mechanism, has been proven to maintain student focus, reduce boredom, and increase learning motivation [21][22]. In addition, this approach also supports collaborative learning, where students can share their understanding and problem-solving strategies in a positive and challenging atmosphere. CONCLUSION The application of QuizWhizzer-assisted Problem-Based Learning (PBL) has been proven effective in improving students' conceptual understanding of buffer solution material. The results of the paired sample t-test and independent sample t-test show a significance value of less than 0.05, indicating a significant improvement after treatment. The N-Gain value showed a moderate increase in both groups: 0.67 for the experimental class and 0.56 for the control class. However, the greater increase in the experimental class proved the effectiveness of interactive media in strengthening conceptual understanding. The CRI analysis showed an increase in the “understands concept” category in the experimental class from 17.3% to 73.2% and a decrease in the “does not understand concept” category from 53.1% to 10.4%, indicating the positive impact of implementing QuizWhizzer-assisted problem-based learning. These findings support the results of previous studies [11][12][16], which concluded that the integration of interactive media in problem-based learning models can improve students' critical thinking, problemsolving, and conceptual understanding in chemistry. REFERENCE MICHAEL KURNIAWAN 9 Study Case MICHAEL KURNIAWAN 10