Floating and sinking (FS) is a key topic in science education, both at primary and secondary levels. The interpretation of FS phenomena, however, is challenging due to the difficulty of the scientific concepts and explanatory models involved (e.g., density, buoyancy), along with students' everyday experiences, which conflict with scientific explanations. Consequently, many studies over the last few decades have investigated how FS could be taught effectively to students of different ages while utilizing multiple teaching approaches. This meta-analysis summarizes findings from 69 intervention studies on teaching FS conducted between 1977 and 2021. Over all studies, we estimated a mean effect size of g = 0.85 (95% CI = 0.71, 0.99). This large effect size demonstrates that, although FS is a challenging concept, teaching FS is effective even in elementary school. Moreover, in a moderator analysis, we investigate the effect of intervention characteristics, students' age, as well as study design, and assessment features on the mean study effect size. To analyze the effect of these moderator variables, we use a three-level hierarchical meta-regression model for dealing with multiple effect sizes from single studies. We found two intervention characteristics that explain variance in study effect sizes: longer lasting interventions result in larger effect sizes and interventions where hands-on experiments are applied are more effective than those utilizing virtual experiments. Furthermore, studies with a treatment-control group comparison have significantly smaller effect sizes than studies with a pre-post design. We discuss the implications of our findings regarding the moderator variables for effective teaching of FS and further research on FS.

中文翻译：

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教学浮与沉：荟萃分析

浮沉（FS）是中小学科学教育的一个关键主题。然而，由于涉及的科学概念和解释模型（例如密度、浮力）以及学生的日常经验与科学解释相冲突，对FS现象的解释具有挑战性。因此，过去几十年来的许多研究都调查了如何利用多种教学方法向不同年龄的学生有效地教授金融学。这项荟萃分析总结了 1977 年至 2021 年间进行的 69 项 FS 教学干预研究的结果。在所有研究中，我们估计平均效应大小为g  = 0.85 (95% CI = 0.71, 0.99)。如此大的效应量表明，尽管 FS 是一个具有挑战性的概念，但即使在小学教授 FS 也是有效的。此外，在调节分析中，我们调查了干预特征、学生年龄、研究设计和评估特征对平均研究效应大小的影响。为了分析这些调节变量的影响，我们使用三级分层元回归模型来处理单个研究的多个效应大小。我们发现两个干预特征可以解释研究效果大小的差异：更持久的干预会导致更大的效果大小，而应用实践实验的干预比使用虚拟实验的干预更有效。此外，治疗组与对照组比较的研究的效应大小明显小于事前设计的研究。我们讨论了我们关于调节变量的研究结果对 FS 有效教学和 FS 进一步研究的影响。