It's summertime at East High School.
The hallways are quiet and a little stuffy, some of them lined with furniture and boxes of books as maintenance crews install new lockers and polish classroom floors.
But step into Ryan Williams' classroom and you'll see a half-dozen students still poring over biology textbooks and contemplating the role of ribonucleic acid in gene expression.
"So, what does RNA do?" Williams asks.
"Uhhhh, something?" a student answers, smiling.
"'Something' is not an answer that will work in this class," the teacher responds, smiling back. "So you should probably look back over the material."
The 14-year-old student failed biology last year — he was a freshman — but he's trying again. So are hundreds more Wichita students who returned to school after Memorial Day in an effort to turn F's into passing grades and stay on track to graduate on time.
This isn't summer school. It's a free and, for many students, much quicker credit-recovery program — the Wichita district calls it "extended school year" — that allows them to redo certain assignments and raise their grade without retaking an entire class.
"Usually it's students who are having a hard time adjusting to high school, realizing that the expectations are a lot higher," said Williams, who teaches biology and Earth and space science.
"We don't just do extra credit and give you tons of makeup work two days before the semester ends," he said. "What we make you do is come here and work. ... The goal is to give them a fresh biology credit, but it's also to help them understand that, you know, there's a function of school."
School districts nationwide are embracing summer school or credit-recovery programs as a way to prevent dropouts and boost graduation rates.
According to an analysis of U.S. Department of Education data by The Wall Street Journal, more than 1 million American high school students took at least one credit-recovery class during the 2015-16 school year. Some credit-recovery classes are taken online; some are led by a teacher or are a blend of the two.
This year for the first time, Wichita allowed high school seniors to enroll in summer school to retake required credits and graduate on time. For that program, students pay $90 per half-credit.
The district was scheduled to hold a combined commencement ceremony Thursday evening for students who earned their diplomas during the summer, either through summer school, credit-recovery or online learning centers.
In Wichita, students must score at least 50 percent in a class to qualify for the free credit-recovery program. Each high school sets its own schedule and course offerings, but most run three weeks and offer at least English, Algebra I and biology. Students can take more than one credit-recovery course if they qualify.
Students work at their own pace, reviewing material and retaking quizzes or tests they failed the first time around. As soon as they do, their final grade is changed, and they can start their summer break.
Some critics question the rigor of credit-recovery classes, saying they're a poor substitute for a full-semester course or that they artificially boost graduation rates.
Others say they make sense for students who fall just short of passing.
Ruthann Harris, an English teacher at East High, said students in her summer English II class reread and reviewed stories they covered in class last semester. "So theoretically, they should finally be getting it," she said.
The class includes students who qualify for special education as well as ones who were enrolled in honors or International Baccalaureate classes. "It's 100 percent mastery on everything, so they keep going back until they get it right," Harris said.
Earlier this week, one sophomore read a passage about the Montgomery bus boycott, answered questions and crafted an "ACE paragraph" using the answer-cite-explain writing strategy to demonstrate her understanding of the material.
Two other students worked with English teacher Celeste Hutton in the hallway, discussing an excerpt from "Caramelo" by Sandra Cisneros.
"The external conflict is: You can't stop time. How is that resolved?" Hutton asked. "How does she demonstrate that she understands that people cannot stop time?"
"She sees the pictures of her father?" one girl answers.
"Right," Hutton says. "So she is accepting the aging process of both herself and her father."
The students nod.
For many students, the one-on-one or small-group instruction they get during summer classes helps them grasp concepts and feel more confident, Hutton said.
"It's neat when you get kids to come in, not wanting to be here, but then they see the pattern and figure it out," she said. "By the end, some of them become independent."
Gil Alvarez, Wichita's assistant superintendent of secondary schools, said most schools have geared their extended-school-year programs to freshmen and sophomores, trying to help them catch up on credits before they get too far behind. But that could change next school year as the district makes graduation rates a top priority.
"When we talk about increasing the graduation rate, that's just another thing we can try to do," Alvarez said.
"It's a way to help students who didn't quite finish. ... Whenever they get their work caught up or do what they need to do, they're done, and they can feel good about that."