Posted by Emma Brown on May 5, 2015.

A dozen civil rights groups issued a statement Tuesday criticizing the growing movement of parents who refuse to allow their children to take standardized tests, saying the anti-test push “would sabotage important data and rob us of the right to know how our students are faring.”

By removing an increasing number of students from the testing pool, the so-called opt-out movement skews test score data, the groups argued, making it impossible to gauge whether persistent achievement gaps are narrowing.

Read the full article on The Washington Post.