On Monday, Gov. Mark Dayton signed a law that will attract new teachers to the classroom and help boost student achievement in Minnesota.

The law, which authorizes the Board of Teaching to approve alternative licensure programs for aspiring teachers, is a bipartisan model of how lawmakers can work together on education to do what's right for children.

At present, a midcareer professional, scientist or military veteran would likely have to return to college to earn a degree in teaching before he or she could become a public school teacher in Minnesota.

But instead of deterring experienced professionals from becoming teachers, states and school districts should be casting a wider net for teaching talent beyond education majors and traditional graduate education programs.

Teach For America, the nation's best-known alternative certification program, has made teaching a hot profession again for an entire generation of bright, committed college graduates. But to operate in Minnesota, TFA had to receive a special waiver.

CareerTeacher -- another innovative certification program designed collaboratively by the teachers union and school district in St. Paul -- will now be able to proceed with preparing midcareer professionals to become special-education teachers.

Both nonprofits and institutions of higher education can run alternative licensure programs under the new law, but only if the preparation programs meet rigorous standards.

Teaching candidates have to have a minimum grade-point average of 3.0, pass a basic skills test, and receive at least 200 hours of student teaching or clinical preparation. Those enrolled in alternative certification programs approved by the Board of Teaching would only receive temporary teaching licenses while in their training programs.

Most important, approved alternative programs have to use a results-oriented approach, training teaching candidates in practices that increase student learning and tracking growth against state standards. The Board of Teaching can revoke its approval for any alternative certification program that fails to meet these standards.

In the end, it is not critical whether teacher preparation is done in an alternative or traditional certification program.

But it is vitally important that all programs prepare effective teachers who advance and accelerate student learning, especially in high-poverty, high-need schools, and for special-needs students.

All programs must prepare teachers to deliver an excellent education and instruction appropriately tailored to English learners and students with disabilities.

Minnesota's new law is a great start toward building more-rigorous teacher preparation programs that provide content expertise, clinical rigor and a more diverse teaching force. Yet unfortunately -- as is the case in most states -- Minnesota's teacher preparation system lacks accountability.

I have encouraged all states to track the impact that program graduates from every preparation program have on student growth, as well as the job placement success and longevity of program graduates in the classroom.

Minnesota does not currently track the impact of teacher preparation programs on student learning. As a result, teacher candidates do not know which preparation programs are effective.

Program administrators do not have classroom feedback to guide them to strengthen their programs.

And state and district leaders cannot ensure that low-income and minority students, students with disabilities, and English learners are not being served disproportionately by teachers from less-effective programs.

Under federal law, the state is required to assess preparation programs and identify low performers. Yet from 2002 to 2007, the most recent year with data available, Minnesota did not identify a single teacher preparation program as low-performing.

The U.S. Dept. of Education's Race to the Top competition encouraged states to remove unnecessary barriers to effective alternative certification programs -- not because alternative licensure programs are necessarily better than traditional ones, but rather because alternative certification laws make room for innovative models, like the union-led CareerTeacher initiative in St. Paul.

Proven alternative certification programs also provide states and districts with new pipelines to effective teachers.

An unusual coalition of Democratic and Republican lawmakers, the Chamber of Commerce, and Gov. Dayton supported Minnesota's new law. It takes political courage to challenge a convenient status quo.

I applaud all those who came together in the spirit of tough-minded collaboration to hammer out a bill and work toward reducing Minnesota's large achievement gap.

The enactment of this law is ultimately a reminder that when it comes to educating children, partisan politics need not and should not prevail. But it is also a reminder that passing legislation is only a first step to making changes in the classroom that boost student achievement.

The effectiveness of the new law will depend largely on its implementation and the quality of the new alternative certification programs authorized by the state. Accountability matters.

As Dayton has said, it will be the Board of Teaching's responsibility to provide the "rigorous approval and review procedures that will be crucial to ensure quality standards for all teachers who are placed in classrooms."

Still, today Minnesota takes an important stride to strengthen the teaching profession and support schoolchildren -- a step that seemed unimaginable to many not that long ago.

Arne Duncan is the U.S. Secretary of Education.