These pressures encourage a kind of defensive rigidity in which practitioners protect themselves from substantial changes by making slight adjustments at the margins, by claiming they have already made the changes that reformers pro-pose, or by claiming that research justifies their existing practices. But the problem of multiple, conflicting, and ill-defined goals is not unique to the United States and does not derive solely from our unique system of governance. Indeed, most other countries have far more centralized systems than we have, but do not have any more evidence of re-search use. Many of them are susceptible to fads-often emigrating from the United States-and all are susceptible to multiple and conflicting goals for their education sys-tems and to shifting policy climates and public sentiments as perceptions of national strengths and weaknesses change over time.