This paper reports the findings of a study exploring the possibilities of improving students’ argumentation skills concerning evaporation process and factors affecting evaporation by implementing two teaching schemes, with and without the use of particle theory. The participants (ages 10/11, n = 77) were students of four fifth-grade classes of two Greek regular public primary schools. The research data were collected through an open-ended written test (pre- and post-intervention) and a semi-structured interview (post-intervention). Results revealed that the improvement of students’ argumentation skills regarding the evaporation process and the factors affecting evaporation is feasible through an appropriate teaching intervention. This concerns mainly the components of claim and evidence, whereas the use of the particle theory seems to contribute further to this improvement, as well as to the improvement of the reasoning component. Implications for science education are also discussed.

The study explored the possibilities to improve students’ argumentation ability concerning factors that affect dissolving, through the implementation of two versions of a teaching scheme, with and without particle theory. The participants (age range 10–11, n = 27) belonged to two fifth-grade classes of a primary school in Northern Greece. Data were collected through an open-ended written test and a semi-structured interview targeting four of the components of an argument: Claims, data, warrants, and rebuttals, for five factors affecting the dissolving of a solid substance in water: Temperature, stirring, amount of the substance, grain size, and nature of the substance itself. Results showed an improvement concerning the structure of students’ arguments, whereas improvements in content quality appeared mainly in some cases where particle theory was implemented. Study limitations and implications for science education are discussed.