Science education literature states that fostering students’ and teachers’ knowledge of NOS has shifted from being a desirable goal to an essential one. This article focuses on the development of NOS conceptions among MA Education students. To develop those conceptions, the researcher designed various learning activities in the context of ​‘research of history on DNA’. Seven students were observed and audiotaped while working in groups in this classroom qualitative study. Before the intervention, pre-test on ​‘views on science’- Chen (2006) and group discussions held with participants indicated that their NOS conceptions were basic. After 7 sessions, a post-test was administered to students asking to justify NOS conceptions. These conceptions: scientifc knowledge is tentative, laws are generalisations or universal relationships, theories are inferred explanations of nature; and that science is empirically based, socio-culturally embedded, and creative. Classroom discourses and responses to a post-test indicated that participants justifed some NOS conceptions very well and some not so very well. It also argues that HOS ofers potential for improved learning of NOS.