The aim of the present study was to investigate the influence of the explicit nature of science instruction embedded in the Argument-Driven Inquiry method compared with an implicit inquiry method on eleventh-grade students’ conceptions of NOS. Thus, two research questions guided this investigation:(1) Does the explicit nature of science instruction embedded in the Argument-Driven Inquiry method help eleventh graders improve their conceptions of NOS aspects?(2) Is the explicit nature of science instruction embedded in the Argument-Driven Inquiry method more effective than an implicit inquiry method in developing eleventh graders’ conceptions of NOS aspects?