Hollywood agents would never cast Zach Cheikho in the stereotypical rebel role. The 16-year-old maintains a 3.5 GPA at Denver’s South High School and speaks in a measured manner that brings to mind airport public service announcements. With his glossy, dark-rimmed glasses, he seems more likely to play the sensitive, bookish kid in a smart, quirky coming-of-age story.

But, as it turns out, Cheikho is the kind of politically motivated rabble-rouser school administrators have come to fear in recent years.

Since the eighth grade, Cheikho has refused to take most standardized tests—and he’s campaigned for other students to boycott testing too. Last March, he spent his lunch periods distributing opt-out letters to fellow students, many of whom signed the handouts and filed them with South High’s leadership. “The tests take a huge amount of time away from actual classwork, and I just feel like I’m being cheated out of my education,” Cheikho told the audience at First Christian Reformed Church in Platt Park, where he was invited to speak as part of an opt-out panel discussion this past May. Fellow panelists included two Denver Public Schools (DPS) parents, two DPS teachers, former DPS board member Jeannie Kaplan, and Peggy Robertson, an Aurora Public Schools teacher who co-founded United Opt Out (a national organization that urges families to “choose to refuse”). “The opt-out movement is about civil disobedience,” said Robertson, prompting applause.

In the nation’s larger school districts, including Denver Public Schools, students take an average of 113 standardized tests each by the time they graduate. Most are administered between grades three and eight, when kids typically take 10—and as many as 20—standardized tests per year. Critics say it’s too much, for many of the same reasons Cheikho cites.

But with students’ test scores determining which schools receive the exalted top status and which get restructured as a result of poor performance, schools do all they can to produce favorable numbers—including pressuring kids to show up. Cheikho, whose mother supports his protests, says South’s administration confiscated his fliers. A parent on the panel says she was told by principal Peter Castillo that her son wouldn’t be welcome at K–12 Kunsmiller Creative Arts Academy the next year if he opted out. (Castillo disputes this account and says students who opt out of testing because of personal beliefs are not penalized.) An audience member later explained how a man removed her daughter from math class, told the seventh-grader she couldn’t return until she took the TCAP test, and wouldn’t let her call her mom when she asked. “The principal at Skinner [Middle School] told all the eighth-graders that they wouldn’t be allowed to walk at their continuation if they didn’t take the tests,” another parent said (Skinner’s principal says no students were denied participation). “Can they do that?”

The response was a chorus of angry replies: “No!”

If you’re savvy to the varying grades of graphite, that’s likely because you grew up taking the Iowa Tests of Basic Skills, which required the use of a No. 2 pencil to fill in bubbles answering multiple-choice questions. Following their 1935 debut, the tests gave administrators and families a way to assess academic achievement based on a national standard. The goal was to give schools the ability to compare results against this standard, so that a test score in Alabama meant the same as the equivalent score in Wyoming.

The No Child Left Behind Act, which former President George W. Bush signed into law in 2002, put some teeth into testing. Federal requirements amount to 17 standardized tests—one each year in reading and math from third through eighth grade, and one round of English, math, and science tests in high school (typically in 10th grade). If students don’t show annual improvement—with, for example, this year’s seventh-graders outscoring last year’s—the school is subject to sanctions, such as allowing students the option of transferring to other schools, replacing school staff, and, after six years without betterment, completely restructuring the school. “An accountability system must have a consequence,” Bush said in 2001. “Otherwise, it’s not much of an accountability system.”

With an increased emphasis on testing, the state and districts have layered on even more exams to try to forecast student performance and boost it appropriately. The 2012 Colorado READ Act instituted three literacy tests each year for kindergarten through third grades (children who are proficient on the first test can skip the remainder of that year’s exams), and districts administer their own interim assessments to get snapshots of how students are likely to fare on year-end evaluations. “We literally have teachers who lose 50 days of instruction every single year because of all the time lost to testing,” says Kerrie Dallman, president of the Colorado Education Association (CEA). That’s 28 percent of a typical 180-day school year.

The testing load has imposed a range of consequences including, Dallman says, a “narrowing of the curriculum and less investment in ‘specials’ classes such as art and music.” Schools’ computer labs are tied up during test sessions, making them unavailable for other students for up to six weeks at a time. In some situations, test scheduling also overrides special education services for kids with disabilities.

“There are many, many serious flaws in No Child Left Behind that need to be fixed,” says DPS superintendent Tom Boasberg.

Some teachers argue that the scores arrive late (in fall for the previous spring’s tests) and don’t shed light on specific areas where students need improvement. The new Partnership for Assessment of Readiness for College and Careers (PARCC) exams—introduced statewide during the 2014-15 school year—promise more nuanced results, but past assessments have only labeled students as “advanced,” “proficient,” or “partially proficient.” Additionally, some test critics object to what they call corporate profiteering: Pearson, a global company that dominates the U.S. testing market, earned $26.8 million for administering the PARCC and other standardized tests in Colorado during the 2014-15 school year.

Frustration with these issues has prompted some families to boycott standardized testing altogether. Schools are obligated to administer the mandated exams, but students aren’t required to take them. Widespread protests in Boulder last November received national media attention and resulted in more than 1,200 seniors declining to take standardized social studies and science tests known as Colorado Measures of Academic Success. Colorado Springs has also seen widespread opt-outs: Only 29 of the 320 juniors at Cheyenne Mountain High School took the PARCC English and math tests, and at Monument Academy, more than 60 percent of the school’s third- through eighth-graders refused to take the PARCC.

Schools fear that if fewer than 95 percent of their students take the tests, their federal funding will be affected. (Schools typically don’t lose the money, but they can be forced to surrender control over how it’s spent.) That’s led some schools, such as Kunsmiller in southwest Denver, to include a testing clause in students’ contracts: By signing it, students pledge to “try their best” on all common assessments. Low test participation may also impact teachers’ compensation because DPS ties test scores to teacher bonuses.

Yet the original goal of Bush’s testing initiative—to improve education for underserved blacks, Hispanics, and poor children—remains something many educators support, at least in the abstract. “There are many, many serious flaws in No Child Left Behind that need to be fixed,” says DPS superintendent Tom Boasberg. “But one of the really important successes of that act was to make sure that data on student progress is broken out by income, by race, by disability, and to really shine a light on students who, historically, have often not received the same quality of opportunities and education.” That’s why, as Congress prepares to revise No Child Left Behind, civil rights groups such as the NAACP and the League of United Latin American Citizens have petitioned to preserve the current testing requirements. With the data these tests provide, Boasberg says, schools can “take steps to change [their] policies, to change [their] approaches, to close those achievement gaps.”

Paul Chavez, a DPS special education teacher who works with first- and second-graders, isn’t convinced. “We’ve been testing for more than 10 years now,” he says, “but the gap has only gotten wider.” Studies bear Chavez out: According to the National Assessment of Educational Progress (nicknamed the “nation’s report card”), score gaps in 2012 were often wider—and only occasionally narrower—than they were before No Child Left Behind was instituted. “Testing identifies the gap,” says CEA spokesperson Mike Wetzel, “but resources close the gap.”

Standing on the sidewalk at East Colfax Avenue and Grant Street, you can peer inside the CEA’s window display and see a series of photos, each with an individual teacher holding a sign. “I teach students to be mindful citizens of our school!” says one. “I coached a student to speak in front of a crowd, and she won queen of the county fair!” reads another. And: “My students learn that mathematics & science reveal the wonder & beauty of their world.” All include the hashtag #morethanascoreco.

Rhetorical hashtags aside, testing is here to stay. The question now facing legislators and educators is: How much testing does it take to satisfy the demand for data? “We’ve been clear that we need fewer and shorter tests,” Boasberg says. Last spring, the state Legislature approved rollbacks that trimmed students’ K–12 test load by about 26 percent. PARCC tests were eliminated for 10th, 11th, and 12th grade, and literacy tests for kindergarten through third grade were reduced. But fourth- through ninth-graders received little relief, and many families and educators still want more testing cutbacks. Some advocate limiting the number of subjects tested. “There’s no need to test every subject,” says East High School science teacher Margaret Bobb. “All you need is a snapshot of kids’ basic skills in reading and math because really, everything flows from there.”

CEA’s Dallman says she believes the solution lies in random sampling. Instead of asking every student to take every test, we could conduct tests like opinion polls by tapping a cross-section of students or by testing in different districts in different years. That would ease the testing burden while identifying systemic problems, Dallman says. The concern—among Boasberg and others—is that random sampling doesn’t hold teachers accountable for every student’s progress.

There is some evidence a one-two punch that follows testing with funding does improve outcomes. Colorado’s youngest students have benefitted from the 2012 READ Act, which uses common assessments to identify children who could benefit from tutoring and summer classes. Such programs received $33 million in state funding in 2014, and early results suggest that one such program, the Colorado Reading Corps (which pairs AmeriCorps volunteers with struggling readers), has markedly raised students’ reading proficiencies. By the time they complete the program, kids who participate in Colorado Reading Corps tutoring are reading at a higher level than their peers who originally scored as proficient, Colorado Lieutenant Governor Joe Garcia told NPR’s Erin O’Toole earlier this year.

But Boasberg himself credits the opt-out movement—and students such as Cheikho—as having fueled the recent legislative changes. (The new laws also stipulate that districts can’t penalize students for opting out of state assessments.) “Anytime you’re having important discussions about policy, having a really vigorous debate and having people challenge assumptions is a very good thing,” says Boasberg. “And I think the opt-out movement has done that.”