A Model-Based Inquiry Activity Using LEGO to Promote System Thinking of Grade 11 Students on Buffer Solution Topic

System thinking in chemistry education aims to prepare future students who can apply the chemistry knowledge to addressing real-world complex phenomenon and have more holistic perspectives. The system thinking skills are divided into three levels: (1) analysis of system components, (2) synthesis of system components, and (3) implementation. In this study, a model-based inquiry learning activity using LEGO was developed in order to promote students’ system thinking on the topic of buffer solutions. In the activity, LEGO was used as a tool for students to simulate systems for representing the pH controlling process in related natural phenomena such as maintaining the pH of seawater, the circulatory system, and the food industry, etc. The activity was implemented for 30 Thai high school students in the science and mathematics program using a one-group pretest-posttest design. A test on system thinking specific to the buffer solution topic and a student's self-evaluation questionnaire on system thinking skills were used as tools for collecting data. An analysis of the three levels of system thinking skills showed that the average posttest score of each level was significantly higher than the pretest score in all levels especially in the synthesis of system components level and students could apply the knowledge to the real-world issues. After the activity, students’ reports from the questionnaire indicated that they could relate each component in the systems and could expand their knowledge to other systems.