In a backlash against Common Core standards, many New York state parents have decided to “opt out” of new standardized tests—and their numbers are snowballing, as the New York Times reports:

Across New York State, a small if vocal movement urging a rejection of standardized exams took off this year, maturing from scattered displays of disobedience into a widespread rebuke of state testing policies.

At least 165,000 children, or one of every six eligible students, sat out at least one of the two standardized tests this year, more than double and possibly triple the number who did so in 2014, according to an analysis by The New York Times.

… At the same time, some education officials and advocacy groups fear, the opt-out movement will reverse a long-term effort to identify teachers and schools — and students — who are not up to par, at least as far as their test performance goes. Of particular concern is that without reliable, consistent data, children in minority communities may be left to drift through schools that fail them, without consequences.

Parents interviewed in the article say that they’re not trying to avoid low test scores, though children’s scores did plummet last year after the new Common Core standards were instituted. Rather, parents said “they felt [tests] put too much stress on students, for example, or because they wanted to make a statement on behalf of teachers.” Under Common Core, teacher evaluations and tenure are both tied to test performance scores. This has resulted in a strong reaction from teachers’ unions and parents throughout New York.

This “opt out” movement can be viewed through two lenses: the first lens is one of concern, because such opting out decreases school and teacher accountability, removing the state’s principal means of judging their performance and impact on kids’ learning. Our ability to judge how well a school is doing is increasingly tied to data, to quantifiable measurements of a student’s progress. As the New York Times put it in an April article,

Critics of the campaigns against testing, including many state and local education officials, say the unions are not acting out of concern for children but are trying to undercut efforts to institute tougher evaluations. They argue that annual testing is critical for tracking how effectively schools are educating poor and minority students and that evaluations based only on subjective criteria like observations typically fail to identify weak teachers.

But the other lens we must consider is a positive one: for those with more libertarian inclinations, this development could be good. It removes educational power from the state, and instead vests it with parents and teachers, who one might argue are a better judge of students’ needs and performance than any test can be. It is worth noting that tests are not always a good judge of a student’s abilities: much depends on the learning style of the student. Many parents and teachers are cautious of standardized tests because they believe that, while tests may quantitatively measure a students abilities, they cannot take into account the qualitative growth of that student.

Homeschoolers have been “opting out” of regular standards for decades. Though many take standardized tests, depending on the requirements of their state, many also avoid such testing whenever they can—as do many private schools.

We must also carefully consider whether tying teacher performance to test scores will truly improve students’ classroom experience. While it may have a positive effect, it may also propel teachers to stick solely to test-related material, thus significantly narrowing students’ learning possibilities. The fear of losing one’s job over standardized tests may even motivate teachers to cheat, as NPR reported last year. Thus, the idea that high-stakes testing provides accountability is tenuous at best. It largely depends on the situation and the teacher. A one-size-fits-all education model may in fact result in less learning and less accountability.

Interestingly, this latter view—that standardized testing can be unproductive or even damaging—seems to be shared by many on both left and right: it appeals to unions, to “parents who object to testing,” and to “Republicans who oppose the Common Core standards as a federalization of education,” as Kate Taylor and Motoko Rich note in their Times piece.

But both pros and cons should be taken into account—as The Onion reminds us in this piece on standardized testing (albeit humorously), there are two sides to the story.