In a quiet classroom tucked on the second floor of a large stone church on Indianapolis’ west side, students at the Excel Center-Lafayette Square took an English quiz, dictionaries strewn across their desks.

French. English. Spanish. Students flipped through the books as they wrote down their answers, lips moving as they silently sounded out words. In this class, all but one of the dozen or so students are new to the English language, and they are working to earn their high school diplomas while balancing jobs and family commitments.

Adult high schools like this one, which cater to students over 18 who previously dropped out or are new to the country, and other unconventional schools that offer more flexibility such as virtual charter schools, are increasingly enrolling more students learning English.

But those schools’ graduation rates are lower than traditional high schools, possibly contributing to a large drop in graduation rates for English learners last year, state officials say.

Read: Find your school’s 2017 graduation rate

Across the state, more than 50,000 Indiana students are learning English as a new language — a number that has been growing over the past couple decades. In adult high schools and virtual schools, that population has exploded from nine students in a handful of schools in 2011, to more than 900 students attending 16 schools in 2017, according to state data.

And last year, the graduation rate for English-learners overall tumbled by about 15 percentage points from the previous year to 61 percent, the lowest it’s been since 2008.

“We are not satisfied with where our graduation rate is for English-learners, and we won’t be until they are achieving at the same level as their English-speaking peers,” said Valerie Beard, assistant director of English learners and migrant education programs for the state education department. “We’re never happy with a gap.”

Beard believes  a growing number of English-learners attending adult high schools and virtual charter schools could contribute to the drops in graduation rate. In her analysis of the state’s graduation data, Indiana would have had about the same rate of English learners graduating in 2017 as in 2016 — about 75 percent — if virtual and adult high school students weren’t factored in.

While the majority of virtual charter schools and adult high schools had too few English-learner graduates to have results publicly reported in 2016, data that is available showed that 12 students earned diplomas at those schools, out of 56 English learners in their graduating classes. The next year, 52 of 339 students graduated. The only school with results available for both years — Indiana Virtual School — saw a decrease from 2016 to 2017, from 5.9 percent of English learners graduating to none. Over the same time period, its total English-learner enrollment nearly doubled from 76 students to 145.

But Betsy Delgado, vice president of mission and education with Goodwill of Central and Southern Indiana, whose nonprofit group runs the Excel Centers, said the way the state has been calculating graduation rate for the Excel Center-Lafayette Square, and adult high schools more broadly, is “an inaccurate representation of the performance of the school.”

The state’s approach, she says, assumes adult students and traditional high school students are all expected to graduate four years after they begin, which runs counter to how adult high schools are held accountable for student performance in other areas, such as state A-F grades. Adult learners might return to school years after dropping out, or need more time to finish, Delgado said.

“What we know is students who enroll in adult high schools, by nature of the program, are working full-time, have kids — they have a lot of complicated factors that make it more difficult,” Beard said. “The fact that the graduation rate is low does not necessarily mean that those schools are not working hard or working well with those students.”

Adam Baker, a spokesman for the Indiana Department of Education, said the state is changing how it reports graduation rates for adult high schools going forward (new data is typically reported in January), a nod to Delgado’s concern. If adult high school students were not included in the 2016 and 2017 graduation rates, the state’s overall rate for English learners would have decreased by 6 percentage points, not 15. But Baker maintains that for those years, the reported graduation rates are “official” and accurate to how the system operated.

The decline in graduation rate comes even as the state has ramped up funding for English learners. From 2015 through 2018, Indiana more than tripled the amount of per-student aid schools can receive for students learning English. But in high schools especially, where new students have far less time to become fluent, getting them to pass state English and math tests — the current requirements to earn a diploma — can be difficult, according to educators.

Jennifer DePaoli, who co-authored the 2018 Building A Grad Nation report, said a shortage of teachers who specialize in students learning English and the complexity of serving students in one building who might speak dozens of languages can also be challenges for schools trying to support English-learners. Across the nation, students learning English graduate at a lower rate than their English-speaking peers. But the rate has improved, up to 67 percent in 2016 compared to 57 percent in 2011.

Read: Teachers connect with language learners with strategy and purpose

Those changes are “really promising,” DePaoli said, but “that doesn’t mean that there isn’t backtracking going on.”

Additionally, as students move through traditional schools, their English proficiency could improve. A student who starts freshman year with English services might no longer need them come graduation. That can make rates for English learners seem lower because those students who no longer need services will be counted among the general graduation rate, though they might be showing improvement overall.

But as Indiana schools adopt new graduation rules that no longer require that students pass state math and English exams to get a diploma, there’s optimism that more English learners can reach the finish line.

The state’s new “graduation pathways” will offer students a menu of options they can fulfill to graduate. Under the system, which will affect students now in eighth grade, the state graduation exam will be replaced with one of several new graduation pathways requirements, which could include passing a college-entrance exam, taking career and technical education classes, or passing advanced courses.

“It’s definitely going to make a difference,” said Nigel Bryant, who leads the Lafayette Square Excel Center. “I think it’s going to open up a lot of doors.”