Jack Schneider is the author of Excellence For All: How a New Breed of Reformers Is Transforming America’s Public Schools.  After completing a fellowship at Carleton College, he will be joining the faculty at Holy Cross.

It is an accepted truism that successful schools offer lessons about “what works” and that those lessons can, in turn, be taken to scale.  It’s a nice, simple idea, and particularly attractive for those put off by the tentative nature of educational research.

And there’s only one problem: it doesn’t work.

The move to identify effective practices and take them to scale is a unique product of the “excellence for all” era—an age in which the traditionally separate concerns of excellence and equity have been fused together.  Prior to that, concerns with “excellence” usually manifested in efforts like tracking, designed to better serve the so-called best and brightest.  “Equity,” on the other hand, was associated with efforts like busing; rather than raising the height of the nation’s educational pyramid, the aim was to level the playing field.

In the mid-1980s, however, these two separate approaches to school reform were bound together as a new corps of politically pragmatic reformers began talking about “excellence for all.”  Equity, they suggested, need not come at the expense of the privileged.  Instead, high flying schools could serve as models for their lower achieving peers.  Identify what makes good schools special, these reformers argued, and reproduce it.

Like reformers of previous eras, those in the “excellence for all” era were drawn disproportionately from backgrounds of educational privilege.  But whereas in earlier eras such lofty educational experiences had been viewed as irrelevant for the work of improving urban public schooling, they became more significant as reformers sought to erase the gap between privileged schools and their urban public counterparts.  As such, reformers increasingly perceived themselves as well-situated to comment on the character of effective schools, relying on personal experience, common sense, and intuition to inform their positions on educational change.

Viewed in this light, the thrust behind efforts like the small schools movement makes perfect sense.  One can almost picture Bill Gates—graduate of a small private school that “made a huge difference” in his life—touring a large urban high school and noting how much bigger it was than his alma mater.  Goaded on by Tom Vander Ark, another private school graduate who frequently cited his own personal experience as an influence, Gates poured $2 billion into small schools efforts, believing that they had found “what works” and could replicate it.

But the small schools movement was not an isolated case of reliance on common sense and personal experience as a means of identifying “what works.”  Consider the popularity of an organization like Teach For America, which won support in government and among major philanthropies by playing up the fact that fixing schools is, in Wendy Kopp’s words, “not rocket science.”  Urban and rural schools, the theory goes, would be better off if their teachers had degrees from places like Harvard—the kinds of diplomas possessed by those teaching at schools like Andover.  It’s a classic overgeneralization error—that a salient factor from one setting would continue to be so in another.  But errant or not, the allure of learning from personal experience and using common sense to draw out lessons is incredibly powerful.  Never mind the fact that most urban high schools look nothing like Andover.

Or take a third example: the effort to expand the Advanced Placement Program.  For the first 40 years of its history, AP was the exclusive domain of tony private schools and wealthy suburban districts.  Consequently, when entrepreneurial reformers began seeking scalable solutions, they saw AP as an obvious example of “what works.”  After all, lots of successful schools used it.  So they began pushing to get AP everywhere, confident it would make a difference.

The results of this approach, not surprisingly, have been less than inspiring.  The small schools movement failed to substantially increase student achievement.  TFA corps members, for all the good work they do, are hardly the kind of life-long expert teachers found at top-flight independent schools, and most studies find them roughly equivalent to other novices.  And the AP Program, having expanded into low-income urban and rural schools, is now being dumped by elite schools and branded as outdated.

Yet despite these mixed results, “excellence for all”-minded reformers are no more skeptical of their work than fish are of the water they swim in.  This generation of “educational entrepreneurs,” after all, came of age believing that successful schools offer particular lessons, and that those lessons can be replicated in entirely new environments.  It is an article of faith.  But like other articles of faith, it sometimes conflicts with reality.