This document reports on a study that compared the explicit approach and ASEI-PDSI approach for teaching science in Swaziland secondary schools. The study aimed to investigate changes in learners' understanding of the nature of science (NOS) after interventions using each approach. Results showed that both approaches improved students' NOS understandings, with slightly more improvement seen in the group that received the explicit approach. However, statistical analysis found no significant difference in outcomes between the two teaching methods. The study concluded that the explicit and ASEI-PDSI approaches were almost equally effective for teaching NOS.