pupil ratio, teacher education, teacher experience, teacher salary, per-pupil expenditure, administrative inputs, and school facilities. He conducted his summary using a synthesis method known as "vote counting." This method essentially involves examining the regression coefficients for the same resource from different studies; categorizing each result according to whether it indicated a positive or negative or zero effect on academic achievement; and tabulating the results to summarize the overall conclusion about the effect of the resource based on all the studies that examined it.
Hanushek's summaries have probably had an impact second only to the original Coleman report itself in persuading people that money (or school) doesn't matter in efforts to improve education. Therefore, it is important to emphasize his point that he cannot find systematic relationships between variations in school resources and student performance. This is quite different from saying that schools and their attributes never matter. As Hanushek has expressed his view in recent work: "This finding of a lack of any general resource relationship is, however, very different from finding that schools have no differential impact. A number of subsequent studies [i.e., subsequent to the Coleman report] document rather conclusively that schools have significantly different effects on student achievement, even if the good schools are not necessarily those rich in traditionally measured inputs" (Hanushek, 1997b:302).
One possible objection to Hanushek's literature review is that the variables he examined did not involve the full array of school-related input measures that might possibly influence student achievement. Monk (1990) reviewed studies focusing on an additional set of school inputs suggested by educational production theory: learning technologies, the uses of time, public versus private organization of schools, and the size of districts and schools. Like Hanushek, he found no conclusive evidence in the literature that these resources systematically contribute to higher student achievement.
For a quarter of a century after Coleman, the dominant view of scholars in the input-output tradition was skepticism about the possibility of finding reliable relationships that could guide policy makers in their decisions about how to allocate resources and organize schools in ways that would lead to improved student academic outcomes. Comparatively recently, the prevailing view that school inputs cannot be unambiguously linked to student achievement has begun to be challenged, although a new consensus about the nature of the input-output relationship has not yet emerged.
A major challenge to Hanushek's work has come on methodological grounds. Hedges, Laine, and Greenwald (1994a) argued that Hanushek's vote-counting method for synthesizing studies results in a bias against finding positive effects of resources on student outcomes. They point, for example, to the fact that while vote counting can be used to summarize the direction and significance of the effects of resource variables on outcomes, it cannot determine the magnitude of any statistical effect.