Three studies carried out at the ETH Zürich give excellent insights into interventions in primary science teaching. In particular the importance of the control of variables strategy and how this effects conceptual change and the learning of scientific principles.

They explore how primary school students develop scientific thinking, specifically focusing on the relationship between domain-general skills (like the control-of-variables strategy, or CVS—the ability to conduct a “fair test” by changing only one thing at a time) and domain-specific knowledge (understanding specific science concepts like physics) (Edelsbrunner, 2017).

How Knowledge Develops: Edelsbrunner (2017) found that children’s scientific reasoning consists of both verbal knowledge (the ability to explain an experiment) and non-verbal knowledge (the ability to actually set up or choose a good experiment). Up until about fourth grade, these two types of knowledge are often disconnected; many young students can successfully identify or apply a fair test, but they lack the ability to verbally justify their reasoning (Edelsbrunner, 2017).
Experimentation Skills Boost Content Learning: When learning about floating and sinking through guided inquiry, students who started with a better understanding of the control-of-variables strategy were much more successful at abandoning their misconceptions and acquiring accurate scientific concepts (Edelsbrunner et al., 2018). Knowing how to experiment acts as a catalyst for learning what the experiment teaches (Edelsbrunner et al., 2018).
Content Learning Boosts Experimentation Skills: Conversely, providing students with a “high dose” of guided, content-focused science experiments (where the teacher ensures tests are valid) has a “collateral benefit” on students’ general skills (Schalk et al., 2019). Even when teachers never explicitly taught the rules of the control-of-variables strategy, students naturally abstracted the rule and became better at applying it to entirely new topics (Schalk et al., 2019).

Implications for Practice my summary of the papers

References

Edelsbrunner, P. A., 2017. Domain-General and Domain-Specific Scientific Thinking in Childhood: Measurement and Educational Interplay. Doctoral Thesis, ETH Zurich.

Edelsbrunner, P. A., Schalk, L., Schumacher, R. and Stern, E., 2018. Variable control and conceptual change: A large-scale quantitative study in elementary school. Learning and Individual Differences, 66, pp.38-53.

Schalk, L., Edelsbrunner, P. A., Deiglmayr, A., Schumacher, R. and Stern, E., 2019. Improved application of the control-of-variables strategy as a collateral benefit of inquiry-based physics education in elementary school. Learning and Instruction, 59, pp.34-45.