activities, but then may move rapidly from data collection to conclusions without giving students time to make sense of the data themselves. Such layering of standards-based approaches on existing practice may be the result of professional development experiences that were neither extensive nor focused enough to bring about deep understanding of the reform and fundamental shifts in classroom practice. Inconsistent implementation of the reform is reflected in contradictions within teachers’ self-reports of their beliefs and practices, as well as between teacher self-reports and independent observations of classroom practice.
In addition to a lack of adequate professional development, factors within and external to the NSES can make it difficult for teachers to align their practice to the vision of the reform. On the one hand, the NSES advocate hands-on/inquiry-based instructional strategies and a “less is more” approach to content. At the same time, the sheer number of topics in the NSES exerts pressure simply to “cover” the content, a stress only magnified in those instances where externally mandated science achievement tests come into play.
It is important to note that there are a number of limitations both in individual studies identified in this search and in the research base as a whole that make it difficult to assess the impact of the NSES at this juncture. Quite a few of the studies are correlational in nature, which further complicates attempts at attribution. Only a few of the studies are based on nationally representative samples, and there is generally only limited information provided about the samples and how they were selected. In addition, only a few studies report information about the magnitude of the results (i.e., effect sizes). As a result, while the literature provides some sense of the nature of the influence of the NSES, there is little information about the extent of that influence, and who is being affected.
As the Framework for Investigating the Influence of the Standards states:
Given the complex and interactive nature of the territory within which standards have been enacted, a mosaic of evidence from many different types of studies is more likely to build overall understanding of the influence of standards than the results of a few purportedly comprehensive studies. (NRC, 2002 p. 94)
To meet this challenge, more research is needed that is purposefully designed to answer questions about the influence of standards and that meets “standards of evidence, quality of measurement, and appropriateness of research design” (p. 89). In addition to using measures of demonstrated validity and reliability in all of these studies, at least some of the research will need to use nationally representative samples. Finally, fuller reporting of research results is needed, including both positive and negative findings, and including effect sizes so that the magnitude as well as the direction of effects can be judged and meaningful cross-study comparisons and meta-analyses can be conducted (Thompson, 2002).
Given the relative newness of the NSES, it is not surprising that few of the studies identified in the literature search were designed specifically to assess their impact; many studies addressed standards-based reform more generally. In addition, as the Framework suggests, the multiple entry points for the NSES to potentially influence the system make it difficult to trace the impacts of the NSES (NRC, 2002).
A major question that remains is what science is actually being taught in the nation’s K–12 classrooms. No comprehensive picture of the science content that is actually delivered to students exists. This lack of information on what science is being taught in classrooms, both before the NSES and since, makes it very difficult to assess the extent of influence of the NSES on teaching practice. Studies such as those employing the Surveys of Enacted Curriculum (Blank et al., 2001) conducted using nationally representative samples, combined with a judicious number of observations to validate the findings, would help in determining the extent of alignment of instruction to the content standards.
Another major question that remains regarding teaching practice related to the NSES is whether the combination of traditional and standards-based beliefs and practices is an interim step in teachers’ progress toward more fully standards-based practice. If so, the research seems to suggest that further progress requires: (1) specific attention to what constitutes standards-based science education in terms of both content and pedagogy through professional development, and (2) communicating a consistent vision of standards-based science education through alignment and quality control of policies and administrative actions that guide instruction.