The data so far provide compelling evidence that:

  • Children in our sample start with macroscopic concepts of weight, size, material and matter at odds with scientists’ conceptions; this supports our assumption that new curricula may be needed to target these conceptual difficulties that are typically overlooked as important in traditional science curricula;
  • Children receiving the Inquiry Project curriculum made clear progress in both grade 3 and grade 4 on multiple aspects of conceptual understanding of matter, weight, volume, and density; these changes provide evidence that they are engaged in a productive, but long-drawn process of reconceptualizing their matter network;
  • Control students (receiving the standard science curriculum used in their school) made very little progress on items calling for major reconceptualization (as opposed to elaboration). This is further evidence that instructional support is needed in developing these ideas; these ideas do not simply come “for free” with development, as some have assumed, nor are they well developed with standard math and science curriculum.

In the sections that follow, we briefly amplify on the above three points. For more details, please see Smith, Wiser, Carraher, 2010.