It’s National School Choice Week, so it seems like a great time to ask this question: If Congress gets rid of the federal mandate for annual assessments in a reauthorization of the No Child Left Behind Act, what does that mean for public and private school choice programs?

Nothing good, say some advocates and educators who support choice programs, including charter schools. After all, how can parents make smart decisions about where to spend their vouchers or which charter schools to pick if they don’t have annual testing data at their fingertips?

“Parents have a right to know how their kids are doing every year,” said John White, the state superintendent in Louisiana, which is home to a robust school choice program. “A test doesn’t tell the whole story but it’s an important indicator, especially for parents who are evaluating school choices for their kids. Advocates for school choice should also be advocates for measuring school quality. It’s hard to get a read on school quality if you don’t have an annual check-up.”

And annual testing has helped charter school authorizers figure out which charter models to replicate—and which should close their doors, beefing up the quality and reputation of the charter sector as a whole, said Alex Medler, the vice-president for policy and advocacy at the National Association of Charter School Authorizers.

“We actually think that charter school authorizers are some of the most sophisticated users of annual testing data,” Medler said. (More on the group’s take in this statement.)

And Nina Rees, the president of the National Alliance of Public Charter Schools, makes a similar argument in this blog post, where she says the best thing about the NCLB law was its focus on closing achievement gaps. In fact, Rees, who served in the U.S. Department of Education during President George W. Bush’s tenure, feels so strongly about the need to keep annual tests in a new NCLB that she got up before dawn last Friday to talk about it on Fox’s morning show, Fox and Friends. (Check out the video here.)

Meanwhile, American Federation for Children, a school choice advocacy organization in Washington that supports private school vouchers, is also in favor of annual testing—at the state level. The group isn’t taking a position on the federal fight because the only federal voucher program is the Washington D.C. program.

But here’s what the AFC has to say about annual testing as a state policy decision:

“Academic accountability results in transparency to parents, policymakers, taxpayers, and donors. Parents must have the information to choose high-quality schools that meet the needs of their children, while policymakers, taxpayers and donors must measure the impact of private school choice programs on academic achievement and attainment,” said Matt Frendewey, a spokesman for the AFC in an email.

So is any of this enough to sway to members of Congress? It may be too early to say. Sen. Tim Scott, R-S.C. is one of the biggest supporters of school choice in the Senate. In fact, Tuesday, he’s reintroducing a bill to beef up the D.C. Opportunity Scholarship program.

And he said at the American Enterprise Institute Tuesday that he would ideally, “in a perfect world” like to see language in Tennessee Republican Sen. Lamar Alexander’s draft No Child Left Behind reauthorization bill allowing Title I money to follow children to a public school of their choice expanded to include private schools. (He’s not sure yet whether he’ll be introducing an amendment to push for that change.)

So does Scott think that the federal testing mandate needs to stay in place to enable parents to make good school choice decisions? Sounds like he’s still mulling it over.

“Good information is helpful,” he said in a quick interview. “How we get it ... that’s where the devil is in the details.”