Teachers in Chicago went out on strike for the first time in 25 years over issues that have resonance in every state in the country, including Maine. As in many states, Maine teachers and state workers are barred from striking, so their discontents don’t become quite as public; state employees have been without a contract for the past 15 months without the LePage administration feeling much need to negotiate.

So the Chicago showdown made for front-page news. Some of factors were clearly local –- such as the abrasive style of Mayor of Rahm Emmanuel, President Obama’s former chief of staff, who’s widely credited with revamping city services, but has demanded concessions from teachers that’s made them bristle.

The primary issues are not pay and benefits, as in most strikes, but Emmanuel’s efforts to open more charter schools and to tie teacher compensation and promotion tightly to student test scores.

In this he has the support of both the Bush and Obama administrations – a rare case where the two most recent presidents seem mostly to agree. Obama’s Education Secretary, Arne Duncan, was previously Chicago’s superintendent of schools, and is pushing the same policies nationally he did when Obama was beginning his rise from city politics to national prominence.

All this would be heartening if charter schools and student test performance were the magic keys to improving education but, alas, they are not. The evidence shows neither is clearly superior to any other way of organizing schools or evaluating teachers, and each has serious drawbacks when used widely.

The charter school question is easier. Though new to Maine, which approved its first two this year, charter schools have been operating for nearly 40 years in other states. The broadest, most objective study of charter schools came from Stanford University in 2009, covering 70 percent of existing charters. It found their performance disappointing – 17 percent of charters showed greater student achievement than their traditional public school counterparts, while 37 percent underperformed; the other 46 percent showed no significant difference.

While individual charter schools are often cited as success stories -– and there are some –- as an educational method it doesn’t inspire further investment of public dollars.

Things get more complicated with test scores. Yes, good teachers often do produce score gains for the students, but such gains are hard to sustain over time, since each class of students is quite different than its predecessors. The single biggest factor predicting student test performance is poverty, and scores will almost always be higher in suburban communities than the inner city.

Indeed, a good argument can be made that we should be sending the best, most highly paid teachers into the poorest neighborhoods, because that’s where they could make the biggest difference -– not that it will happen any time soon.

By the time you factor in all the variables and uncertainties, it’s clear that test scores are not nearly the objective, scientific data that some reformers would like them to be. Basing teacher contracts on them is not likely to produce better schools, and is likely to produce continuing turmoil.

We do know what actually produces good results in education, and rigorous testing regimens don’t work in schools any better than they would in most workplaces. Successful schools almost always have strong principals who are involved with students, combined with mentor relationships between experienced and novice teachers that build good classroom technique. Good schools have supportive, involved parents and stable, highly motivated staffs. None of these things are produced by teaching to the test.

You might think the big problem in public schools is that there’s too much “deadwood,” teachers ready for retirement who have already mentally checked out. That was the theory of new-wave superintendents in cities like New York and Washington, D.C., who argued that firing lots of teachers would improve school performance. It didn’t.

In fact, teaching is such a demanding job that 50 percent of first-year teachers have left the profession by the end of year five. This is a far higher burnout rate than among doctors, lawyers, accountants  or most recognized professions. The teacher turnover dilemma parallels the odd debate about voter fraud — a largely nonexistent problem in a nation where barely 60 percent of citizens vote, even in presidential election years.

American public schools in many ways do a remarkable job in dealing with a population that is extremely mobile and multi-lingual, and has high rates of poor, single-parent families. Schools have much room for improvement, of course, but they will get better through slow, patient building of parent support, staffing and funding – not through imposing the latest educational gimmick on unwilling educators.