State College, Pennsylvania (CNN) -- A Pennsylvania mother has decided she does not want her two children to take the two-week-long standardized tests given by her state as part of the federal No Child Left Behind law. And she hopes other parents will do the same.

Michele Gray's sons -- Ted Rosenblum, 11, and John Michael Rosenblum, 9 -- did independent study the week of March 14 while their classmates were filling in hundreds of bubbles in classrooms with doors marked, "Quiet. Testing in Progress."

Gray says the only legal exemption that would allow her kids to sit out the tests was a religious objection. So that's what she did.

But Gray says her concerns go well beyond religion. "The more I look at standardized tests, the more I realize that we have, as parents, been kind of sold a bill of goods."

She says the tests are not accurate measures of accomplishment, create undue anxiety for students and are used to punish schools.

She gives the example of her sons' award-winning school, Park Forest Elementary, which last year was put on "warning" status after the school's special education students fell below the level of progress the state expects on their exams.

"The more I looked at it, the more outraged I became," Gray said, "This is not something I want to be contributing to (or) something I want my children participating in."

Dr. Timothy Slekar, an associate professor of education at Penn State Altoona, agrees. It was his op-ed piece on the Huffington Post website that inspired Gray to take action.

Slekar is also a father and this year chose not to allow his 11-year-old son Luke to take the tests. He says schools are narrowing their curricula in an effort to boost test scores and wasting too much time preparing for, and then taking, the tests.

He says the tests aren't an accurate indicator of a child's -- or a school's -- performance. "I'm a father and an educator who's finally said, 'This is it. I'm done.' Something has to give. Something has to change," Slekar said.

Another education professor, Dana Mitra, also isn't happy with the tests, but decided to allow her third-grader daughter to take them this year because she's afraid that holding her daughter out could harm the school's test results.

"Given that we're interested in wanting our schools to be the best that they can, we feel pressure as parents to want to help our school," she said. She's not sure what she'll do with her daughter next year.

Testing proponents, such as United Negro College Fund President and CEO Michael Lomax, say parents who opt out "are doing their own children a disservice." He added, "Testing is a parent's ally" and that in order to compete with countries such as China and India, U.S. schools need to be held to a higher standard. And testing, he says, is the way to do it.

"The testing isn't the reason the schools are failing. The instruction is the reason the schools are failing," Lomax insisted.

But "opt-out" parents like Gray and Slekar are undeterred.

Gray has a Facebook page aimed at helping other parents learn that they are able to opt out of testing and how to do it.

Parents in Colorado have created a similar website.

Despite these efforts, opting out of standardized tests is rare nationwide. The U.S. Department of Education says it doesn't track the numbers.

At Park Forest Elementary, where Gray's children go, nine out of 500 were held out of standardized tests this year, including Gray's. Last year, all the students there took the test.

President Barack Obama, at a March speech at a Virginia school, acknowledged testing reform is needed. But he says testing isn't going away.

"There will be testing," he said. "We can have accountability without rigidity -- accountability that still encourages creativity inside the classroom, and empowers teachers and students and administrators."

His administration recently announced a $300 million grant aimed at revamping standardized tests.

Meantime, Ted and John Michael won't be participating. Their mother thinks if enough parents follow her lead, high-stakes testing may go away altogether.

Michael Lomax thinks parents like Gray are hurting education. "I'm sure they love their kids," he said, "but I think they are wrong."