Model-based analysis of the impact of a teaching-learning sequence about carbonated drinks on students’ understanding of the dissolution of gases in liquids

This research integrates context-based learning and modelling. It presents a teaching-learning sequence (TLS) about the dissolution of gases in liquids using carbonated drinks as the context. The impact of the TLS is analysed in a longitudinal short-term study involving two groups of learners aged 13–14 years old (<i>n</i>=53). The results led us to infer five models explaining how carbon dioxide is distributed in a carbonated soft drink, categorized and ordered by increasing complexity as follows: <i>Gas apart; Bubbles; Bubbles and something else; Dissolved gas</i>; and <i>Oversaturation</i>. Some of these models reflected preconceived ideas based on students’ personal experience, while others emerged from the teaching. Three clusters of students were identified based on the frequency with which their responses were included in the models <i>Dissolved gas or Oversaturation</i>. Overall, the TLS shows potential as a framework for enhancing students’ knowledge. This is reflected in the fact that more advanced models of dissolution became increasingly identifiable in their responses as they worked through the activities, while less sophisticated ones were observed less frequently. Overall, nearly two-thirds of them demonstrated that they had acquired an understanding of the concept of dissolved gas. Some of the activities used seem to be particularly helpful in this respect.

本研究融合了基于情境的学习与建模方法，提出了一项以碳酸饮料为情境的气体在液体中溶解的教学序列（Teaching-Learning Sequence, TLS）。本研究针对两组13-14岁的学习者（n=53）开展短期纵向研究，以分析该教学序列的实施效果。研究结果推导得出五种解释二氧化碳在碳酸软饮料中分布规律的模型，按复杂度从低到高依次归类排序为：「气体分离；气泡；气泡与其他物质；溶解态气体」以及「过饱和状态」。其中部分模型反映了学生基于个人经验形成的前概念，其余模型则源于本次教学活动。研究基于学生作答归入「溶解态气体」或「过饱和状态」模型的频次，识别出三类学生群体。总体而言，该教学序列具备作为提升学生学科认知的框架的潜力，具体体现为：随着学生完成各项教学活动，其作答中体现的高级溶解模型占比逐渐提升，而低阶模型的出现频次则逐步降低。整体而言，近三分之二的学习者展现出对溶解态气体概念的掌握，本次研究采用的部分教学活动在这一目标上展现出尤为突出的辅助效果。