There have been substantial reform efforts in science education to improve students' understandings of science and its processes and provide continual support for students becoming scientifically literate (American Association for the Advancement of Science in Benchmarks for science literacy, Oxford University Press, New York, 1993; "National Research Council in Mathematics and science education around the world," National Academy Press, Washington DC, 1996; National Science Teachers Association in NSTA position statement 2000). Despite previous research, it is still unclear whether young children are actually developmentally ready to conceptualize the ideas that are recommended in the reforms (Akerson V, Volrich M (2006) "Journal of Research and Science Teaching," 43, 377-394). The purpose of this study was to explore how explicit-reflective instruction could improve young students' understanding of NOS. During an informal education setting, the authors taught NOS aspects using explicit-reflective instruction. Overall the students participating in the program improved their understanding of the target aspects of NOS through use of explicit reflective instruction. However, the levels of improvement varied across different aspects. Students improved the most in their understanding of the tentative nature of science and the roles of observation in scientific work, although there was still some confusion regarding the distinction between observation and inference. More work needs to be done exploring these specific topics and the role explicit reflective practice can play in identifying the particular problems students have in distinguishing these constructs.