Stop letting bad school systems experiment with reform. Make them imitate one of the more successful systems instead. Here's how it would work.
1. Define the demographic categories that will be applied to each school system. This would be things like the total population of students served, the relative economic status of those students, the transiency rate, ethnic mixture, etc...
2. After the demographic criteria has been defined, group the school systems according to their similarities. Using states as examples, this would most likely put California, Texas, Florida, New York and New Jersey into the same group.
3. Rank the states in each group according to how their students performed on nationally-normed tests.
4. After the rankings have been established, only allow the top three states in each group to experiment with improving their educational system. Any state that isn't in the top three for their group will be required to pick one of the top three states and duplicate that educational system that that state uses (in its entirety).
5. Repeat steps 1 through 4 every five to ten years.
By making this reform measure a part of each state's constitution we could be sure that those states with poor educational systems were at least moving in the right direction. The lowest performing districts have already proven that they can't make wise choices. This forces them to follow those who have proven their ability to make wise choices.
The top three districts may or may not want to experiment. They probably didn't get to the top by being satisfied with where they're at - leaders tend to think there's always room for improvement. (The fear of falling behind might also motivate those who tend to favor the status quo into competing with the experimenting leaders to make sure they don't fall behind.)
Here are some examples of experiments that might be worth making:
1. Use all of the tools that are available in reading programs instead of just the bandwagon of the day. Right now many school systems choose either phonics, whole language, etc... Each approach works with a certain number of students but by limiting themselves to only one approach the students that that approach doesn't work for get left behind. (This might have something to do with the economics of buying a single type of textbook.)
2. Require all schools to follow the thematic approach, where each subject is taught in the context of changing themes (this would reinforce the subject matter throughout the day).
3. Allow students to test their way out of any and all subjects. This would mean changing the system from grade-based classes to knowledge-based classes. When you passed all of the tests you'd graduate, regardless of your age.
4. Make all subjects beyond basic reading and math electives. You wouldn't have to pass algebra to graduate if the direction your career was taking wasn't likely to use it. There would still be a requirement for an overall number of credits - you'd just pick courses that were relevant to your goals. (The first two years of college in the U.S. could stand an improvement along these lines.)
5. Change the current curriculum to subjects that make more sense in a modern world.
a. Drop the wood shop class and replace it with a home repairs class.
b. Drop an algebra class and replace it with a logic class.
c. Drop an English class and replace it with a class exposing the techniques used in modern advertising and propaganda.
d. Change a history class from its emphasis on people and dates to a class on world timelines and concurrent cultural development.