Iowa sets a low bar for the tests that new teachers must pass to get a job, while some states have raised standards.

The contrast reflects an Iowa philosophy that tests are a poor predictor of teacher talent, especially in a state where educators are highly sought after.

Critics say Iowa has missed an opportunity to make sure new teachers have mastered their subjects at a time when the state's share of disadvantaged students is growing and Iowa has slipped in some national rankings.

While most states embrace tests for all prospective teachers, Iowa gets by with the minimum:

• Iowa is one of two states that do not require tests for would-be middle and high school teachers.

• Prospective elementary teachers in every state must pass tests under federal law, but Iowa officials set the nation's lowest cutoff score on their most-used test. The score was recommended by a panel of Iowa educators.

• Pass-fail rates are made public in many states, but Iowans have no way to gauge how prospective elementary teachers fare. State officials don't track test scores, despite a federal law that says states must report results of licensing exams to the U.S. Department of Education.

Iowa education officials claim the tests are tied to teacher preparation programs instead of state licensing, so they believe the federal reporting rule does not apply.

Republican lawmakers have backed bills to tighten Iowa's teacher test requirements, but they haven't caught on at the Legislature.

A pair of bills that would have required new middle and high school teachers to pass standardized tests died this session.

"We do not have a valid, reliable, systematic way of ensuring that teachers that go into the classroom have content knowledge," said Senate Minority Leader Paul McKinley, R-Chariton, who pushed one of the bills. "It is a serious problem that indicates that we don't place the kind of emphasis we need to on student achievement."

Judy Jeffrey, the state's top education official, said teacher preparation programs provide much better checks and balances than a test score.

"Our teachers are highly recruited by other states," Jeffrey said. "They will sign them up without even an interview."

Most states raised expectations for teachers following a landmark 1983 report that showed "a rising tide of mediocrity" in the nation's schools.

Teachers are the main ingredient in a student's success at school, research shows, and tests were viewed as a way to apply uniform standards to aspiring educators who had not yet proven their skills in the classroom, said Dan Goldhaber, a University of Washington education professor.

"They've been used for a long time in most places," Goldhaber said. "The controversy over them in Iowa is an outlier."

Nearly all states - although Iowa, Nebraska and Montana were exceptions - adopted tests for teachers by the time the federal No Child Left Behind law passed in 2001.

The No Child Left Behind law included a rule that new elementary teachers had to pass a test before they were hired.

That rule does not apply to prospective middle and high school teachers who declare academic majors in their subject areas, but most states adopted tests for those teachers anyway. Iowa and Nebraska remain exceptions.

A representative of the National Council on Teacher Quality explained why tests are considered a better measure of whether a new teacher has mastered subject matter than an academic major.

"A major tells you a person has a lot of course work in a particular area, but there's no way of knowing if that course work actually matches up with the state's content standards," said Sandi Jacobs, vice president of the National Council on Teacher Quality, a research and advocacy group. "A test is a much clearer way to be sure that an individual knows the content you want them to know."

While teacher tests are viewed broadly as a good idea, the exams used by most states have been criticized as too easy or as weak predictors of good teachers.

"I really see this as analogous to the use of college entrance exams to determine who gets into college," said Goldhaber, the University of Washington professor. "It's useful to look at, for instance the SAT, but you probably want to look at it in conjunction with all the other information that you can learn about the applicant."

Iowa education leaders experimented with teacher tests years ago before ruling them out.

William Callahan, dean of the University of Northern Iowa's education college, said the federal law was designed for other states with mediocre teacher preparation programs and a large share of poor, minority and otherwise disadvantaged students.

Callahan said UNI and other schools already stretch beyond course requirements and use student teaching experiences to weed out iffy teacher education students.

UNI students who have questionable grades, temperaments or approaches to teaching are flagged by faculty members who draw up "contracts" that force students to fix problems before they are awarded diplomas, he said.

"Graduating from our program means you're going to be a good teacher 99.9 percent of the time," Callahan said.

Iowa graduates also are scrutinized in their first teaching jobs: They start out on probationary licenses, and their bosses - school officials - can refuse to recommend them for full licenses.

Those safeguards were part of the case state education officials built for remaining a "non-testing state."

That approach worked until 2006, when federal officials threatened to strip the state of millions of dollars in education money unless leaders adopted a test.

Iowa's prospective elementary teachers started taking tests the following year.

Some educators believe federal officials eventually will order tests for prospective middle and high school teachers in Iowa.

Jacobs, of the national teacher quality group, points to huge gaps in test scores between Iowa's white students and their low-income and minority counterparts.

"Iowa has an achievement gap like every other state," Jacobs said. "These policies are necessary to protect the most disadvantaged kids, and that's really where the state's responsibility should lie."

But two Iowa educators believe the current system works.

Tom Narak, superintendent of the West Des Moines school district, believes the state doesn't need more testing for prospective teachers.

"The culture in Iowa for education is very strong, and I think that probably sets us apart," he said. "If we were experiencing teachers coming out of our colleges and universities that weren't well prepared in the content, I probably would think differently."

Sarah Wessling, a Johnston High School English teacher, said most standardized teacher tests fall short because they call for "recall and regurgitation" instead of critical thinking.

"There's so much more to learning than content knowledge," said Wessling, who was named Iowa's teacher of the year in 2009. "To assume that a standardized test can determine whether or not someone is ready or capable for a classroom is to reduce the professionalism of teaching."

Nearly all states use exams developed by Educational Testing Service, but comparisons are difficult because states set their own pass-fail scores.

Seventeen states use the Praxis II exam that Iowa adopted for most new elementary teachers.

The multiple-choice test measures their grasp of reading, math, science, social studies, arts and physical education, along with their understanding of how to teach those subjects.

Test-takers receive one composite score.

Jeffrey, who heads the Iowa Department of Education, could not explain why Iowa's cutoff score for passing is lower than the other states, but she said a test score can't predict how effective a teacher will be.

"Does a good test-taker make a better teacher?" she said. "There's no research that says that."

ETS officials said their tests aren't designed to predict success, like college entrance exams.

The tests "represent the minimum of what a person needs to do no harm" in the classroom, said Ines Bosworth, the nonprofit's client relations director.

Some researchers say the tests' minimum standards don't live up to the federal law's push for "highly qualified" teachers.

Many states are taking steps to improve tests instead of lobbying to scrap them.

About 20 states are pushing for "performance-based" tests that go beyond multiple-choice tests to gauge how well prospective teachers plan, teach, evaluate student work and adapt their teaching to students' needs, U.S. Department of Education officials say.

Other states have taken steps to develop more challenging standardized tests.

Massachusetts became the first state to require passing scores on math-specific tests for all prospective elementary and special education teachers.

The state, which developed its own teacher tests, had the highest ranking on national math tests for students in fourth and eighth grades in 2009. Iowa's ranking in eighth grade math has dropped from first to 28th since 1992.

Massachusetts education leaders said the shift is one in a long line of reforms that emphasize science, math and other subjects that students need to master in a global economy.

"This new test will have an impact because the quality of teachers, their knowledge of the subject and their capacity to help students reason and apply their subject knowledge is the No. 1 factor in improving student achievement," Massachusetts Department of Education spokesman J.C. Considine said.

Florida officials want to require passing scores in all subjects of elementary tests, instead of a composite, before a teacher is licensed.

"Testing is not the only thing we require for licensure, but it does hold our teachers to a very high standard," said Kathy Hebda, the Florida education department's deputy chancellor for education quality.

"It's part of having high expectations for the students and seeing those through all the way to our teachers and principals."