With the arrival of spring comes the inevitable wave of standardized tests, as public school students across the country break out their number two pencils and spend hours of class time taking math and literacy assessments.

But a growing movement of principals, parents, and teachers is rising up against these exams. They claim that placing so much time and emphasis on high-stakes tests robs students of valuable learning time and unfairly tangles teachers' performance evaluations with meaningless test scores. The opt out movement is gaining momentum through written protests from districts and principals, through social media, including a Facebook group called Parents and Kids Against Standardized Testing, which has more than 1,700 fans, and Occupy Protests at the Department of Education.

This vocal group is raising its voice at least partially in response to ten years of No Child Left Behind, the federal law that requires all public schools to administer standardized tests. Parents in the movement say teachers spend too much time teaching to the test while neglecting long-term projects or more creative learning strategies. They say the tests measure only what students know at a given time, not what we should be defining as "learning."

"Our schools are faced with contradictory and incomplete directives regarding high-stakes testing and evaluation."

Each school, district, and state follows different policies for testing requirements, and it's not necessarily common knowledge to parents that they can choose to opt their children out of taking these tests. In some schools, assessments determine grade promotion, qualification for gifted and talented programs, teacher evaluations, and even funding. Schools are on the hook to test at least 95% of their students every year in order to be eligible for federal funds.

But awareness of opting out is growing in pockets around the country. In Texas, hundreds of school districts are signing on to a resolution against these tests. As of April 26, 412 districts representing more than 2 million students had signed on.