DENVER — Spring is state testing time for schools and students in Colorado and across the country, but there are some parents who are refusing to let their kids participate. They’re part of a movement that began in Colorado and has grown nationwide.

This weekend, United Opt Out National, which started in Colorado four years ago, is holding a national conference in Denver. The goal is to help educate parents on how to protest high-stakes testing tied to school accountability and student progress.

For some families, opting-out is nothing new. Grace and Sophie Engel admit they don’t know much about taking state tests.

“The other kids are always making comments, ‘How come you don’t have to take TCAP?'” said Grace Engel, a junior at Arapahoe High School.

The girls’ mother, Angela Engel, has the answer.

“I’ve opted them out of testing from the beginning,” Angela Engel said.

In 1997, Angela Engel helped administer the state test known as the Colorado Student Assessment Program, CSAP, while she was an elementary teacher in Douglas County.

“I was really on board,” Angela Engel said. “And then I got the test.”

After growing frustrated with the format of the CSAP, Angela decided to opt her daughters out a few years later when the legislature tied test performance to school accountability.

“The emphasis is not around nurturing the relationships between teachers and students and teachers and parents,” Engel said. “It’s around getting the score.”

For schools in Colorado, there is no opting out. The score is the law.

“The schools and districts have the obligation to try and test their kids if the student is in attendance on a testing day,” said Joyce Zurkowski, Executive Director of Assessment for the Colorado Department of Education.

Despite the state law, Zurkowski admits that schools sometimes need to find better ways to accommodate parents who refuse testing.

“I think, perhaps there have been some missteps,” Zurkowski said.

A recent incident at DPS Hill Campus of Arts and Sciences is just the latest example of one of the missteps.

Susan Johnson, who kept her daughter home during testing, captured cell phone video of a confrontation with school administrators after discovering that they had refused to allow her daughter to rejoin her class even after testing was complete.

The Non-profit education website Chalkbeat Colorado first reported the details of the confrontation.

DPS later issued an apology and guidance to all schools that said, in part, “Students refusing to participate in testing should still be allowed access to all other non-assessment activities.”

“You do not close your doors on kids, that’s not an option,” Zurkowski said. “Schools and districts cannot exclude kids from coming into their buildings to receive their education.”

According to CDE, opt-outs are still rare — representing roughly one percent of all students. However, Zurkowski admits that the numbers may increase this year as the state ushers in new trials for a test that aligns more closely with the Common Core next year.

“There is definitely a bit of a surge in parents expressing concern,” Zurkowski said.

Many of those parents in Colorado and across the country have turned to United Opt Out National.  Though the website started locally, it now offers guides for opting out in each state.

Engel said supporters include both progressives and conservatives who share a dislike for the increased emphasis on high-stakes testing and national standards like the common core.

“This is really the moment for parents to say, not with my child, not with my tax dollars you don’t,” Engel said.

According to the CDE the opt-out movement could lead to penalties for school if participation falls below 95 percent. Zurkowski says parents also need to consider what the tests offer families.

“It’s what allows you to get outside of your one individual school, and be able to answer the question, ‘How is my son or daughter doing compared to other kids across the entire state,'” Zurkowski said.

This year 16-year-old Grace Engel did have a chance to compare herself with her peers for the first time. She took the PSAT in preparation for college.

“I was kind of nervous,” Grace Engel said.

It turns out she had nothing to worry about. She scored in the 92nd percentile and she now has a stack of letters from colleges across the country.

“I think it just shows that a non-traditional approach is also very effective in terms of getting into colleges and being successful,” Engel said.

For more on this weekend’s opt-out conference, follow continuing coverage at co.chalkbeat.org.