By virtue of its connection with scientific literacy, the nature of science has been considered essential subject matter for the science curriculum. With this in mind, seventh-grade students were introduced to three aspects of the nature of science: (1) the distinction between observation and inference, (2) the subjective, and (3) the tentative aspects of the nature of science (Lederman et al., 2002). These three aspects of the nature of science were incorporated into lessons on the characteristics of living things. (Contains 5 figures.)