It happens in many thousands of schools each year: A job opens up, and a bunch of teachers apply. How is the principal supposed to know which one not only seems promising in an interview, but is actually going to perform well in the classroom?

That’s the question that TeacherMatch has set out to answer.

The four-year-old company says that its proprietary screening tool — the Educators Professional Inventory — can accurately predict whether a prospective hire will be an effective teacher, and more specifically whether they will be able to boost students’ test scores.

And now the company is poised to expand.

PeopleAdmin, which says it provides human-resources software to school districts that employ one out of every three teachers in the nation, announced Tuesday that it has acquired TeacherMatch and plans to offer its screening tool to its clients across the country.

The two companies have the same ethos, said PeopleAdmin CEO Kermit S. Randa, who described them both as a “disruptive force for good, a way to go out and do well with technology.”

“At the end of the day you want to get the best people, you want to get them up to speed as fast as possible, you want to engage them and have them perform at their best,” Randa said.

The purchase price was not disclosed.

It is a controversial concept, this idea that a questionnaire can identify whether a person is going to be good at teaching before ever stepping into a classroom.

Much of the education establishment has spent years gnashing teeth over how to judge whether teachers are effective based on the work they’ve done in the classroom — let alone whether they might be effective in the future.

Kate Walsh, president of the National Council on Teacher Quality, a nonprofit advocacy and research group that specializes in teacher evaluation and teacher workforce policies, said it’s impossible for her to judge whether TeacherMatch is offering a reliable product because its survey and algorithms are proprietary.

“We don’t know whether their predictive analytics are accurate,” she said. “It might be snake oil or it might be great.”

TeacherMatch executives said if Walsh had asked for more information about the company’s methodology and analytics they would have shared it with her. They said they commonly share information not publicly available with prospective clients and research partners. They added that they have shared their data set and analyses with several university-based researchers who are planning to publish their results.

The company was co-founded by two former Chicago Public Schools officials: Donald J. Fraynd, a Chicago principal who went on to build the district’s school turnaround office, and Ron Huberman, a private equity manager who served as CEO of Chicago schools in 2009 and 2010.

Huberman said the company enlisted the help of researchers who analyzed reams of data on student performance, looking for teachers whose students consistently made large gains on standardized tests and teachers whose students consistently did not make those gains.

Then the company surveyed both kinds of teachers, looking for patterns in the way they answered questions about how they might respond to classroom misbehavior, for example, or how they might teach a certain academic standard. That work became the backbone of the inventory now used in dozens of districts.

Huberman emphasized that TeacherMatch does not recommend that districts hire solely on the basis of an applicant’s survey score. But it should be one part of the decision, he said.

Jason Hammond, human resources director for Phoenix Elementary School District #1, said every prospective teacher there is required to fill out the TeacherMatch survey. Scores are used to rank applicants. “The higher the score, that prioritizes which candidate you want to go after first,” he said.

His district turned to TeacherMatch three years ago as it was struggling to retain teachers. Since then, he said, there’s been a significant decline in teacher turnover, and he sees a correlation between an applicant’s TeacherMatch score and their effectiveness in the classroom.

“We’re moving away from that gut feeling, or just needing something to fill a position, and moving more into that scientific realm,” Hammond said.

This post has been updated.