On a recent Wednesday evening, Leandra Handfield spent her graduate-school class practicing delivering an English lesson, fine-tuning it and getting feedback from professors and peers. The next morning, she taught it to her class of seventh graders at Mastery Charter Prep Middle School in North Philadelphia.

Welcome to Relay Graduate School of Education, a new and controversial kind of teacher-preparation program whose prominence is rising in the city. The School Reform Commission recently approved a $150,000 contract with Relay to train 20 teachers to work in the Philadelphia School District, and signaled that it wants to expand the partnership.

Relay has positioned itself as a disrupter. It has no buildings and few Ph.D.-level faculty. It de-emphasizes theory and academic research. It was founded by three charter-school networks in 2011 and is unaffiliated with any college or university.

"What sets us apart from other schools is there's a focus on practice," said Shemanne Davis, Relay Philadelphia & Camden's founding dean. "The 'why' is important, but what moves teachers is the 'how' - 'how do I do this and put it in practical terms?' "

Relay is interested, it declares on its website, in hiring those passionate "about revolutionizing how educators are prepared for long, successful careers in schools and classrooms."

Superintendent William R. Hite Jr. said choosing Relay will help Philadelphia schools attract more teachers who look like their pupils, a priority for the district, which is made up of 86 percent minority students but just 31 percent minority teachers. More than half of Relay's graduate students are teachers of color.

But critics say Relay's focus is too narrow, that it is too prescriptive, too focused on testing and preparing teachers for work in one kind of charter school only -- that it is more a training program than a graduate school.

SRC member Christopher McGinley, a former superintendent and current Temple University education professor, voted against awarding the contract to Relay, citing concerns with "the quality of services that they're known to provide." (Temple applied for the contract Relay was ultimately awarded, but McGinley said he was not aware that his employer applied to provide the services.)

Seton Hall University professor Daniel Katz, who studies new-teacher induction and chairs the education department, went a step further.

"What Relay is preparing people for is to work only within schools that operate on tightly  scripted curricula," Katz said. "They're not working to teach teachers to be flexible, professional enactors of curriculum, but to work within a set of instructional gimmicks."

In Philadelphia, 20 aspiring teachers -- men and women with bachelor's degrees but no teaching background -- will participate in a two-year program, working with a partner teacher in their first year and leading their own classroom in the second. They will emerge with a Pennsylvania state teaching credential.

Relay is authorized to grant degrees in nine states nationwide, but Pennsylvania is not one of them. It had applied for permission to offer degrees, and state officials at one point recommended that the application be denied, citing concerns about the academic qualifications of Relay's faculty,  and about its lack of a research component. Relay ultimately withdrew the application; Davis said it will eventually reapply.

Relay is expanding quickly, and though it still educates mostly charter teachers in urban areas, it aims to prepare teachers for work in all sectors. In addition to Philadelphia, it has contracts to train educators to work in traditional public schools in San Antonio and Denver.

Relay relies on a blended learning model; its students do about 40 percent of their work online and the rest in evening, weekend, and summer classes. It also keeps costs low. In Philadelphia, the district will pay Relay $7,500 per student annually.

"We don't spend a lot of money on facilities, and we don't have inflated faculty salaries, or administration salaries," said Davis. "We spend a lot of our money on curriculum design and improvement."

On a recent Wednesday, about 40 Relay students -- all working educators -- gathered at  Mastery Charter School-Pickett Campus in Germantown for a 90-minute session with three instructors. The group was diverse and young. The topic of the day was "closing" -- how to effectively wrap up a lesson -- and the class started with a mock lesson delivered by Sam Biddle, a Mastery teacher who is a Relay adjunct instructor.

Students consulted handouts while Biddle assumed the role of a fifth-grade teacher leading a class in writing persuasive essays. When Biddle wrapped up the short role-play, the graduate students jumped in: It was good that Biddle didn't do all the talking. Next time, the wrap-up should be shorter.

"Think about the lesson you're teaching today," Biddle said. "What are you going to do to keep it brief?"

Then, they split up into three groups for "scrimmages": The students practiced lessons on one another. There were finger snaps to indicate a point well-made. A faculty member stood nearby, holding a small clock and keeping time.

For Handfield, the new Mastery-Prep teacher and Relay student, the class was enormously helpful. Like many Relay students, she didn't head straight into the classroom after graduation.

Handfield, 29, looked at  more traditional graduate schools, but Relay sold her -- and not just because it has a partnership with Mastery, which subsidizes her tuition.

"Their values matched mine," said Handfield -- "prioritizing serving the most underserved learners, holding the bar high."

Neither Handfield nor her classmate Michelle Day, who works at St. Malachy's School in North Philadelphia, miss the more traditional hallmarks of education schools.

"As a first-year teacher, I need as much support as possible," said Day, 25.

Davis takes issue with the criticism of Relay as lacking educational quality. The school points to its 2014 New York master's degree graduates as an example of its results: over 90 percent of students of those 300 graduates demonstrated academic improvement, officials said. Broader data is not available because Relay is fairly new, they said.

Davis suggested that the criticism was linked to the fact that Relay prepares mostly minority teachers.

"We live in a world where we expect little of many people of color, but I do believe that teachers of color can do high-quality work," Davis said. "We are actively creating a space that is affirming for teachers of color."

Katz, the Seton Hall professor, agrees with many of the critiques Davis and others have of traditional schools of education: they do not train enough teachers of color, they do not forge enough community partnerships, he said.

Still, Relay isn't the fix, he said.

"We need to do better, but the model for doing better is going to be one that focuses on teachers being contemplative and reflective when they have space to grow over time," Katz said.

But Davis said that the Philadelphia school system will do well with Relay, and that although the teacher-prep program has focused on urban centers largely, it can and will go elsewhere.

"A teacher at Relay is far-better equipped to teach anywhere than any other teacher," Davis said. "It's just good teaching."