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 (n=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: Gas apart; Bubbles; Bubbles and something else; Dissolved gas; and Oversaturation. 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 Dissolved gas or Oversaturation. 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.本研究将基于情境的学习与建模方法相结合，提出了以碳酸饮料为情境载体的气体在液体中溶解主题的教学序列（teaching-learning sequence，以下简称TLS）。本研究针对两组13至14岁的学习者开展短期纵向研究（样本量n=53），分析该TLS的教学影响。研究结果推导得到五种解释二氧化碳在碳酸软饮料中分布机制的模型，按复杂度由低到高依次归类排序为：气体分离型、气泡型、气泡与其他物质型、溶解气体型以及过饱和型。其中部分模型源自学生基于个人经验形成的前概念，其余则由教学活动催生。根据学生回答归入溶解气体型或过饱和型模型的频次，可将受试学生划分为三类集群。总体而言，该TLS展现出作为提升学生学科知识的教学框架的潜力：随着学生完成各项活动，其回答中高阶溶解模型的占比逐渐提升，低阶模型的出现频次则逐步降低，这一现象印证了上述潜力。整体来看，近三分之二的学生已掌握溶解气体的概念内涵，部分教学活动在这一过程中展现出尤为显著的辅助效果。