This study explored the impact of an intervention program designed to enhance upper elementary and middle school students’ nature of science (NOS) views: empirical NOS, tentative NOS, imagination and creativity, social and cultural embeddeness and subjectivity, and the distinction between observation and inference, along with their personal epistemological beliefs under four-dimension epistemic belief scales: source of knowledge, certainty of knowledge, developments of knowledge, and justification of knowledge. The intervention was implemented through a combination of explicit-reflective decontextualized (content-free) NOS lessons and contextualized (within content) inquiry-based science activities.

The analysis of the NOS survey in conjunction with the transcripts of individual interviews, personal epistemology survey, and the video-recordings of the classroom activities revealed that after participating in the intervention young students made substantial gains in their views of some target NOS aspects: specifically observation versus inference and tentative NOS and that even young students were able to make significant progress in developing more sophisticated epistemological beliefs through explicit-reflective instructional approach. Although, there was not a strong relationship found between students’ NOS views and personal epistemologies, many students slightly improved their personal epistemologies toward more sophisticated in parallel to the development of their NOS views.

The above findings in young students’ NOS views and personal epistemologies are taken as evidence of the effectiveness of an explicit/reflective NOS instruction. To improve young students’ NOS views and personal epistemologies, the analyses of the classroom videos and NOS and epistemic surveys suggested that (1) duration of intervention should be longer, (2) teachers should intentionally plan to teach NOS within inquiry lessons, (3) teachers should be provided continued support in their NOS teaching, (4) teachers should also plan interesting activities and demonstrations to engage young students’ minds to the NOS concepts during contextualized inquiry lessons, and (5) epistemic beliefs should also be explicitly targeted as well.