may not immediately recognize the problem of the impact of an invasive species on a local woodlot as one they should care about. They might require additional information about why this problem should matter to them, such as having the teacher illustrate the concept of interdependence in ecosystems—that is, showing that all species, including humans, are linked and therefore the impact of an invasive species has broad and important implications. In this way, a bridge is built between what students do know and do care about and the problem they are attempting to make a meaningful connection with. For example, a study of the motion of light (a common topic in the K-8 curriculum) might require that students first recognize that the motion of light is critical to understanding how telescopes, eyes, and cameras function. Subsequent lessons on such topics as describing and modeling light motion with vector diagrams may then be presented in an investigative context that students see as meaningful.
In order for problems to continue to be meaningful throughout an investigation, careful thought must be given at the outset to how to sequence instruction. Students will need to develop their ability to work on increasingly complex problems, including gradually acquiring knowledge of the concepts being studied and the specific skills needed to carry out a given investigation. A common but limited approach to sequencing investigations has been to teach the content related to the investigation first, and afterward to do the investigation in order to validate the content. This approach is counterproductive on a number of levels. First, it fails to give students a clear idea of why a particular investigative strategy is being used for that particular problem. It also emphasizes and promotes the false dichotomy between scientific content and process, leaving students with the misconception that scientific practice is algorithmic or procedural. Finally, it fails to recognize the critical aspects of science identified in Strand 3 and Strand 4, namely, the importance of reflecting on one’s own scientific knowledge over the course of an investigation and the role of peers in building scientific arguments.
A more productive approach is to intentionally build the appropriate scientific knowledge and skills “just in time,” at strategic points throughout the investigation. When presented at the point in the investigation at which they can be applied, new ideas, as well as new investigative skills and techniques, will be framed in a more meaningful context. In many cases, students will need quick