Ummuhan Ormanci
The growing emphasis on 21st-century competencies highlights the need to develop students’ systems thinking and problem-solving, particularly in science education, where many concepts involve complex, dynamic relationships. This study examined differences in fifth-grade students’ systems thinking performance and problem-solving perceptions associated with simulation-supported science instruction within the unit Electricity in Our Lives. A quasi-experimental pretest–posttest design was used with two intact classes, in which the experimental group received PhET-supported instruction and a control group followed the national curriculum. Data were collected through a systems thinking test (multiple-choice and open-ended items) and a problem-solving perception scale. The results showed that, after adjusting for baseline scores, the simulation-supported group demonstrated higher posttest systems thinking scores than the control group, with a large effect size. For problem-solving perceptions, the simulation-supported group also showed higher posttest scores compared to the control group. In addition, a moderate positive correlation was observed between systems thinking performance and problem-solving perceptions. Although causal inferences are limited due to the use of two intact classes and the absence of individual-level random assignment, the findings suggest that interactive simulations may support students’ holistic reasoning and engagement in problem-solving processes. The study highlights the potential value of integrating interactive simulations into science curricula to promote deeper cognitive competencies.