Every two years, the release of data from the National Assessment of Educational Progress (NAEP) generates a wave of research and commentary trying to explain short- and long-term trends. For instance, there have been a bunch of recent attempts to “explain” an increase in aggregate NAEP scores during the late 1990s and 2000s. Some analyses postulate that the accountability provisions of NCLB were responsible, while more recent arguments have focused on the “effect” (or lack thereof) of newer market-based reforms – for example, looking to NAEP data to “prove” or “disprove” the idea that changes in teacher personnel and other policies have (or have not) generated “gains” in student test scores.
The basic idea here is that, for every increase or decrease in cross-sectional NAEP scores over a given period of time (both for all students and especially for subgroups such as minority and low-income students), there must be “something” in our education system that explains it. In many (but not all) cases, these discussions consist of little more than speculation. Discernible trends in NAEP test score data are almost certainly due to a combination of factors, and it’s unlikely that one policy or set of policies is dominant enough to be identified as “the one." Now, there’s nothing necessarily wrong with speculation, so long as it is clearly identified as such, and conclusions presented accordingly. But I find it curious that some people involved with these speculative arguments seem a bit too willing to assume that schooling factors – rather than changes in cohorts’ circumstances outside of school – are the primary driver of NAEP trends.
So, let me try a little bit of illustrative speculation of my own: I might argue that changes in the economic conditions of American schoolchildren and their families are the most compelling explanation for changes in NAEP.