Regardless of the various “problems” associated with reaching consensus on the various aspects of nature of science, and issues created by the tentativeness of the construct itself, the nature of science has been the object of systematic educational research for approximately 50 years. Prior to this review, there were three reviews of research related to the teaching, learning, and assessment of the nature of science (Abd-El-Khalick & Lederman, 2000a; Lederman, 1992; Meichtry, 1992). In addition to revisiting the contents of previous reviews, this review builds on these prior works and, it is hoped, provides some guidance for future research in the field. For practical reasons, the research reviewed is restricted to published reports and to those studies with a primary focus on NOS. These studies have been divided into obvious thematic sections and are presented in a general chronological sequence within each section.