Four papers by learning scientists engaged either in design research or cognitive-developmental studies consider concreteness, context, content, pedagogy, and situativity and their implications for design that fosters opportunities for students to learn subject matter through experiencing authentic scientific/mathematical inquiry. The authors furnish both theoretical considerations and recent classroom- and laboratory-based empirical findings to question prior interpretations of students' capacity to model and abstract from situations, to generate examples, to transfer, and to make insightful connections. The papers jointly suggest that even simple objects may nevertheless undergird emergent situativity that provides sufficient context to which learners can bring diverse personal resources. Model-based design may be as intellectually honest, culturally respectful, cognitively generative, and scientifically/mathematically authentic as learning that draws more directly on students' out-of-school resources. The authenticity of 'authentic inquiry' may depend more on engagement and reasoning it enables than on specific content and a priori "good-science" practices it recruits.