ChemSims: using simulations and screencasts to help students develop particle-level understanding of equilibrium in an online environment before and during COVID
ChemSims: using simulations and screencasts to help students develop particle-level understanding of equilibrium in an online environment before and during COVID
复制标题
ChemSims：使用模拟和截屏视频帮助学生在新冠疫情之前和期间对在线环境中的平衡进行粒子级理解
DOI：
10.1039/d2rp00063f
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发表时间：
2022
影响因子：
3
通讯作者：
Sweeder, Ryan D.
中科院分区：
文献类型：
--
作者：
Herrington, Deborah G.;Hilborn, Shanna M.;Sielaff, Elizabeth N.;Sweeder, Ryan D.
平衡对许多人来说是一个具有挑战性的概念，很大程度上是因为发展对平衡的深刻概念理解需要有人能够将物理上无法观察到的粒子的运动和相互作用与宏观观察联系起来。粒子级化学动画和模拟可以支持学生将粒子运动与宏观观察联系起来，但对于平衡等主题，通常会提供额外的视觉效果，如图表，这会增加额外的复杂性。帮助学生理解这些视觉效果需要仔细的脚手架，以吸引他们对重要特征的注意，并帮助他们在表示法(例如，粒子运动和图形表示法)之间建立联系。此外，随着学生带着不同程度的背景理解进入我们的课堂，他们可能需要或多或少的时间来处理这样的模拟或动画，以发展所需的概念理解水平。本文描述了利用PHET模拟“反应和速率”来将平衡的概念介绍为学生的课前活动的活动的开发和测试，这些活动可以是直接使用模拟的形式，也可以是由教师通过截屏视频来指导的形式。对这些活动的两个最新实施的岗位前分析表明，无论教师、机构或教学环境的类型(面对面或远程)，学生对平衡背后的核心理念都有更好的理解。我们还观察到，如果学生之前接受过碰撞理论的课程教学，他们在应对压力(如浓度和温度的变化)时，更容易对平衡系统中的变化提供粒子级解释。最后，我们观察到，学生在解释平衡将如何应对施加的压力时，往往侧重于初始反应或注意力的长期稳定性，而不是这两个关键方面。
Equilibrium is a challenging concept for many, largely because developing a deep conceptual understanding of equilibrium requires someone to be able to connect the motions and interactions of particles that cannot be physically observed with macroscopic observations. Particle level chemistry animations and simulations can support student connections of particle motion with macroscopic observations, but for topics such as equilibrium additional visuals such as graphs are typically present which add additional complexity. Helping students make sense of such visuals requires careful scaffolding to draw their attention to important features and help them make connections between representations (e.g., particle motion and graphical representations). Further, as students enter our classrooms with varying levels of background understanding, they may require more or less time working with such simulations or animations to develop the desired level of conceptual understanding. This paper describes the development and testing of activities that use the PhET simulation “Reactions and Rates” to introduce the concept of equilibrium as a student preclass activity either in the form of directly using the simulation or guided by an instructor through a screencast. The pre-post analysis of the two most recent implementations of these activities indicates that students show improved understanding of the core ideas underlying equilibrium regardless of instructor, institution, or type of instructional environment (face to face or remote). We also observed that students were more readily able to provide particle level explanations of changes in equilibrium systems as they respond to stresses (such as changes to concentration and temperature) if they have had prior course instruction on collision theory. Lastly, we observed that student answers to explain how an equilibrium will respond to an applied stress more often focus on either initial responses or longer-term stability of concentrations, not on both key aspects.