The fact is that, in the absence of either large-scale empirical proof of success or the existence of compelling and documentable standards, there is reason to be cautious. The traditionalists are nervous for good reason. It should be noted, however, that the resistance to change is not based on the purported success of current curricula (one is hard-pressed to find people who say that we are doing things well!), but on the fear that the replacement will be even worse. Here it is worth returning to the notion of a zero-based curriculum planning process. Suppose we declared that any proposed curriculum must, in order to be implemented, make a plausible case that it would do well. The reform curricula would fail because they cannot yet produce real proof, or real standards. But current mainstream curricula would fail even more strongly because there exists a massive body of evidence indicating that they do not work. Conclusion: we can not and must not inhibit the extensive field testing of well designed reform curricula, but we must at the same time be vigilant. Good ideas - functionally, ideas that receive the endorsement of a significant proportion of the knowledgeable community - should be tried, but the trials should proceed, as suggested in the section on content, with the highest standards of honesty.