South Valley Academy students protest after leaving class Monday in Albuquerque. New assessment tests that have angered parents and teachers across the nation prompted the walkouts. (Roberto E. Rosales/AP)

A growing number of parents are refusing to let their children take standardized tests this year, arguing that civil disobedience is the best way to change what they say is a destructive overemphasis on tests in the nation’s public schools.

The resistance comes as most states roll out new tests aligned to the Common Core academic standards and as Congress struggles to rewrite the federal law that has defined the role of testing in schools for the past decade.

Parents opting out of tests say that their children are losing valuable learning time as teachers prepare them for the exams, which some find of dubious value. In pulling their children out of exams, they see an opportunity to make a statement that they hope will force a course change on testing in statehouses and in Washington, though the symbolic act itself doesn’t get their children any additional instruction.

“What I’m hearing from the opt-out parents is maybe this is the last chance to get the legislature’s attention,” said Mark Neal, an Ohio superintendent who is an outspoken critic of the new Common Core tests.

Neal pulled his son, a third-grader, out of PARCC testing this year — one of the Common Core exams — as did the parents of about 20 percent of students who were supposed to take tests in his small district east of Columbus.

Mayfield High School junior Laura Cruz, 18, looks up at the sign she is holding during a student-organized walkout to protest the PARCC exams in Las Cruces, N.M., on Monday. (Robin Zielinski/AP)

“We’ve never had anything like this before,” Neal said. “We’ve never had this many tests, we’ve never spent this much time testing.”

State education officials around the country have been urging families to allow students to sit for tests, arguing that the exams provide information that schools need in order to improve and that parents need in order to understand a child’s academic progress.

We hope that parents will want their children to take the test. And not just because it’s required. This is a chance for children to shine, to show what they’ve learned, and — in the bigger picture — do something that will even help improve their hometown schools,” said Michael Yaple, a spokesman for the state education department in New Jersey, which began administering PARCC this week.

Joining Ohio and New Jersey in using PARCC this year for the first time are the District, Maryland and eight other states. Administered online, PARCC is designed to require more writing and critical thinking than the old bubble tests. In many states, it is expected to be more challenging.

The opt-out movement comes in response to the accountability push in education, which aims to boost student performance and close achievement gaps by using test scores to judge schools, teachers and principals.

The accountability era began in earnest in 2002 with the passage of the federal law known as No Child Left Behind, which required states to administer annual reading and math tests to children in grades three through eight and once in high school, and it continued with the Obama administration’s push to include student test scores in teacher evaluations.

Parents and teachers have long argued that attaching ramifications to testing have warped education, forcing schools to focus on math and reading at the expense of social studies, science, art and music.

The new Common Core tests — designed to set and evaluate common benchmarks nationwide — appear to have fueled that frustration and brought new voices into the coalition opposing tests, including some conservatives who decry the Common Core as federal overreach.

Though a symbolic move, opting out has the potential for real consequences that vary by state and by school district.

Skipping the tests has no impact for most individual students, but federal law says that at least 95 percent of students must participate in tests. The rule is meant to keep administrators from quietly discouraging low performers to stay home on exam day, something that could skew performance upward and hide racial or socio-economic inequities.

Schools and school districts that fail to hit 95 percent participation risk losing their federal funds and could see their ratings drop on state report cards.

Nearly every state has groups of parents boycotting the tests, but it is impossible to know how many parents are refusing tests nationwide, because many states neither collect data on it nor have clear policies describing whether and how parents may choose to have their children sit out of testing. The movement remains a tiny minority nationwide, but there are hotbeds where it has grown rapidly.

In New Jersey, where unions have been sponsoring television advertisements highlighting teachers’ concerns about PARCC, some districts have reported that more than a quarter of students are refusing the test. In New Mexico, hundreds of high school students walked out of the first day of PARCC testing last week; the number of parents refusing tests doubled in Albuquerque from last year to this year.

“We have a right to public education, and we don’t want it to just be tests all the time,” said Janelle Astorga, an 18-year-old senior who organized the walkout at Albuquerque High.

Mark Gilboard, an Albuquerque parent who had his fifth-grade daughter sit out of PARCC, said he was flabbergasted when she came home from school recently saying that she and her classmates had spent an hour sitting in front of computers to make sure that the technology was ready for the new online exams.

“They’re using up classroom time to test the test,” Gilboard said. “My thing is, how do we get these children the uninterrupted instructional time that they need from their teachers?”

New Mexico officials said that they expect more than 200,000 students to complete the test this year. The fraction of parents who refuse the test are losing “a valuable tool to know with confidence how their children are doing academically,” said Ellen Hur, a spokeswoman for the state education department.

On Capitol Hill, lawmakers from both parties have railed against overtesting during hearings on rewriting No Child Left Behind. Legislation to reduce testing passed in Virginia last year and is pending in statehouses around the country, including in Maryland, where Gov. Larry Hogan (R) said last week that he thinks children are overtested.

In Ohio, both houses have passed legislation that would ensure schools don’t lose state funding because of opt-outs. State lawmakers also announced Wednesday that they were creating a committee to study testing and recommend changes.

John Marschhausen, a superintendent who will serve on that committee, said he has been encouraging parents not to boycott tests this year despite his concerns about the degree to which testing has interfered with education. He said he wants to give the democratic process a chance to work, and only 105 of his 16,000 students have opted out this year.

“We have elected officials who we put in places of authority and give the ability to make decisions. We should be able to work through them,” Marschhausen said. “But if we don’t see any changes, then my position might be a little bit different in the future.”

Amanda Ripley, who studied education systems in other countries for her 2013 book, “The Smartest Kids in the World,” said there’s an irony that parents are protesting just as the Common Core tests are being introduced, given the hope among many educators that the new tests will spur richer instruction.

“On one side, you have a group of reformers who say that getting rid of federal mandates for annual testing would be apocalyptic, and that’s crazy,” she said. “On the other side, you have people who think that getting rid of it would lead to utopia. I think both sides have lost their minds on this.”