Surrounded by her class of fourth-graders, Jasmine Zeppa filled a bucket with brown water and lectured her pupils on the science of observing and recording data. Many of the children seemed more interested in nearby geese, a passing jogger and the crunchy leaves underfoot.

And the entire process was recorded on video.

Aspiring teachers like Zeppa are preparing for new, more demanding requirements to receive their teacher license. Under a new system being tested in 19 states, video of student teachers in their classroom will be evaluated and candidates must show they can prepare a lesson, tailor it to different levels of students and present it effectively.

Most states only require that would-be teachers pass their class work and a written test. Supporters of the new system say the Teacher Performance Assessment program is a significant improvement, while others are a little more cautious in their praise, warning that it's not guaranteed it will lead to more successful teachers.

The assessments also place responsibility for grading the would-be teachers with teams of outside evaluators who have no stake in the result. Currently, the teachers-in-training are evaluated by their colleges, which want their students to get their teaching licenses.

"It's a big shift that the whole country is going through," said Misty Sato, a University of Minnesota education professor who is helping adapt the assessments for Minnesota. "It's going from 'What has your candidate experienced?' to what your candidate can do."

Minnesota is scheduled to be the first state to adopt the new system when it implements it in 2012. Four other states — Massachusetts, Ohio, Tennessee and Washington — plan to implement it within five years. Fourteen more states are running pilots.

The teacher assessment program is a joint project by a consortium made up of Stanford University, the American Association of Colleges for Teacher Education and the Council of Chief State School Officers.

Sharon P. Robinson, president of the AACTE, an umbrella group for schools that specialize in training teachers, said the assessment will mean better teachers — and ultimately more successful students.

The assessment was developed at Stanford's Center for Assessment, Learning and Equity. Ray Pecheone, the center's executive director, said more than 12,000 teaching candidates have gone through it in four years of testing in California.

California and Arizona are the only states that currently require performance testing to license teachers. Two of California's three different performance tests use video review. The third California test and the one in Arizona requires evaluators to sit in the classrooms and observe the teachers-in-training.

Pecheone said once more states adopt the program the consortium plans to track the performance of teachers who passed the assessment to see if they perform better than teachers who went through the old licensing process.

Karen Balmer, executive director of the Minnesota Board of Teaching, said the assessments will mean more accountability for teaching colleges. For the first time, she said, her agency will have independent data that shows how well those schools are preparing students. Those that consistently produce low-performing graduates could be ordered by the state to improve their programs.

Balmer said the student teachers will pay some of the cost of the new program — probably around the $70 they now pay for the written test in Minnesota. At least initially, students will take both tests, but Balmer said the state may consider dropping the written test in the future.

Students that bomb the assessments would likely be required to retake them. If they do not test again, some teachers could still get a Minnesota teaching license if their college determines there were special circumstances — such as if the student was ill — and recommends licensure, Balmer said.

Tom Dooher, president of the Minnesota's teachers' union said the group supported it because of its emphasis on developing real-world teaching skills. "This is what education reform should look like, for practitioners by practitioners," he said.

Others are taking a wait-and-see attitude about the program.

Sandi Jacobs, vice president of the nonpartisan National Council on Teacher Quality, said she would support any test that could predict who will be a good teacher, but she's not sure performance assessments are it. Too often, she said, the passing scores on such assessments are set so low that nearly everyone passes and the weakest teachers aren't held back.

For Zeppa, the prospective teacher, the pondside session with the rambunctious fourth-graders was just practice for when she goes through the assessment process in spring 2012. She said it's making her a better teacher, even if the process can be painful.

"It's nerve-racking, the idea that every mistake you make is on film," she said.