Teachers' "curricular role identities" are those dimensions of their professional identities concerned with the use of curriculum materials. In a previous study, we developed and tested a survey instrument designed to measure preservice elementary teachers' development of curricular role identity for science teaching through their use of science curriculum materials. In this follow-up study, a revised version of the survey was administered to a second group of preservice elementary teachers in the same science methods course, and data were analyzed within and across years. Results from this study suggest that preservice teachers articulated important similarities and differences between the curricular role identities for science teaching they attributed to themselves and to more experienced elementary teachers. Over time, they were often able to begin to appropriate the curricular role identities for science teaching that they attributed to more experienced elementary teachers. However, findings from the second survey administration also suggest that preservice teachers' curricular role identities for science teaching are more stable when characterized by their actual curriculum design practices than when characterized by comparative, probabilistic means. These findings have important implications for science teacher education and curriculum development, as well as the operationalization of curricular role identity in education research.