Abstract: Numerous studies document that students struggle to comprehend complex, dynamic systems (CDS). Following a design-based research framework, this paper reports two empirical studies that have used personalized and adaptive online interactive learning environment (OILE) to scaffold and measure the progressive development of students’ skills in solving complex, dynamic problems. The findings of the studies show that when scaffolded using OILE, students made statistically significant improvement in their complex problem-solving performance compared to those who were not. Sample results from students’ progress logs demonstrate that the students’ performance had improved in their subsequent tasks. In light of supportive evidence from the empirical results and the students´ progress logs, the paper concludes that the use of personalized and adaptive OILE to support learning in and about CDS is promising.