This paper outlines the development of a framework--the Science in Schools (SiS) Components--that describes effective science teaching and learning and that has become a central focus for the Science in Schools Research project that is being implemented in 225 Australian schools. The description is in a form that provides a basis for monitoring change, and which can be validated against project outcomes. The SiS Components were partially based on interviews with a small number of primary and secondary teachers identified as effective practitioners, and have been subject to a variety of validation processes. The focus of this paper is on a particular form of validation involving interviews with an expanded set of effective primary teachers, from three Australian states. Case descriptions of core elements of these teachers' beliefs and practice were constructed, and a review and mapping process used to examine the extent to which the SiS Components, as a distinct 'window into practice', align with and capture these core elements, and differentiate the practice of these effective teachers from other primary teachers in the project.