The development of students’ argumentation competence is one of the major aims of science education and everyday problems, such as decisions on the consumption of tap water or bottled water, which may be suitable contexts to encourage it. Citizens consider of interest certain controversies associated with the bottled water consumption as an alternative to tap water, which has a significant effect on several aspects of their daily lives. Deciding whether or not to drink bottled water can be used as an interesting context for science teaching activities. To make appropriate decisions on this issue, students must know how to argue with scientific rigour. This paper presents an assessment of the degree of performance of 14/15-year-old students in scientific argumentation within this context. A specific rubric has been designed for each of the assessment activities used, and the Rasch model has been applied to analyse the degree of difficulty that each of the essential elements of an argument (evidence, justification, and conclusion) has for the students. Thus, evidence is generally shown to be the most difficult element of the argument for students followed by justifications and finally conclusions. The analysis procedure used can help to establish a sequence of argumentation activities within a particular context. Finally, the results obtained can be used in teaching to prepare the appropriate assistance according to the argumentation activity at hand.

中文翻译：

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使用 Rubrics 和 Rasch 模型评估 14/15 岁学生在争论瓶装水消费方面的困难

培养学生的论证能力是科学教育和日常问题的主要目标之一，例如决定饮用自来水或瓶装水，这可能是鼓励它的合适环境。市民们对与作为自来水替代品的瓶装水消费相关的某些争议感兴趣，因为自来水对他们日常生活的几个方面都有重大影响。决定是否喝瓶装水可以作为科学教学活动的有趣背景。为了在这个问题上做出适当的决定，学生必须知道如何以科学严谨的方式进行辩论。本文在此背景下评估了 14/15 岁学生在科学论证中的表现程度。为每个使用的评估活动设计了一个特定的量规，并应用 Rasch 模型来分析论证的每个基本要素（证据、理由和结论）对学生的难度。因此，证据通常被证明是学生论证中最困难的要素，其次是理由，最后是结论。所使用的分析程序有助于在特定背景下建立一系列论证活动。最后，所得结果可用于教学，根据手头的论证活动准备相应的辅助材料。和结论）对学生有帮助。因此，证据通常被证明是学生论证中最困难的要素，其次是理由，最后是结论。所使用的分析程序有助于在特定背景下建立一系列论证活动。最后，所得结果可用于教学，根据手头的论证活动准备相应的辅助材料。和结论）对学生有帮助。因此，证据通常被证明是学生论证中最困难的要素，其次是理由，最后是结论。所使用的分析程序有助于在特定背景下建立一系列论证活动。最后，所得结果可用于教学，根据手头的论证活动准备相应的辅助材料。