The study I'd like to see

Studies of charter schools across the country, like this new one, have shown mixed results.

Focusing on math and reading scores, the authors find compelling evidence that charters under-perform traditional public schools in some locations, grades, and subjects, and out-perform traditional public schools in other locations, grades, and subjects. However, important exceptions include elementary school reading and middle school math and reading, where evidence suggests no negative effects of charter schools and, in some cases, evidence of positive effects. 

Charters can be good, or not so good; but some are really good, but some exceptions exist.

But I think the studies (and the one referenced here is just a study of the literature from other studies) are largely focused on the wrong thing, and therefore leave several questions unanswered.  And we need the answers to these questions.  After all, I'm not a charter school advocate as much as I'm a quality education advocate, and I think that the choice represented by charter schools (as well as other forms of choice) will have a positive impact on public education as a while.  (I define public education as all the resources available to the public that can educate children.)

Here's what I'd like to see answered:

• Is there a model of charter school that works better than others?  Looking at all charters in aggregate will of course result in a mixed bag of outcomes.  That's the nature of new models--some work and some won't.  Let's identify the models of curriculum, teaching, governance, and practices that actually get positive results.
• What are the results of all education when charters come around.  I don't care that charter schools compare better or worse than any other school.  I care that students at all schools compare better than they did a few years ago.  Part of the rationale of choice is that the establishment schools will respond to competition by offering programs and improvements that parents value.  There's anecdotal evidence (see Park City's all-day kindergarten and Alpine's move away from Investigations math) in Utah that such happens, but the studies all compare performance between schools, instead of trends over time.
• Finally, how satisfied are parents?  If parents are happier with more choices, and the results are at least comparable, what should we do at that point?  Do we say that parents can't have choice because society judges the value as not much different, or do we continue to let parents exercise choice because they're getting at least something they want out of the bargain?
• And one more, how do different levels of autonomy and freedom affect performance.  Utah's charters are held to almost all the same hiring requirements, reporting requirements, licensure requirements, funding mechanisms, and all that as public schools.  What about states where charters have more flexibility in whom they can hire as teachers?  Or more flexibility with dollars?  If we're serious about finding new models of education, let's really pull the strings off and let schools innovate like crazy.  Unfortunately, there's no currently existing model to allow for such a study, so let's create one.

We need answers.