The U.S. Department of Education has launched a $3 million randomized-control trial to gauge the effectiveness of Khan Academy, the now-ubiquitous online-learning site that popularized the "flipped classroom" model.

WestEd's Science, Technology, Engineering, and Mathematics division was awarded the grant to study the use of Khan Academy's online tutoring library in community college math classes.

Starting in the 2015-16 school year, California community college algebra teachers who are not already familiar with the program will be randomly assigned to either use the Khan resources or their regular practice. WestEd researchers Yvonne Kao and Steve Schneider, the director of its STEM program, will track students to determine whether those in classes using the Khan resources are more likely to complete Algebra I, as well as identify teacher training, course structure and other factors that affect how well the materials are integrated into the larger course.

Khan Academy, a nonprofit online tutoring library featuring video lessons and diagnostic tools, has exploded in popularity since founder and former hedge-fund manager Salman Khan started calling for teachers to use it to give students lectures at home to free class time for more hands-on projects. The site's video lessons later came under criticism for faulty explanations in some videos, but it gained additional traction with lessons aligned to the Common Core State Standards and test-prep for the SAT.

"Until now, there has never been a rigorous, large-scale efficacy study of Khan Academy, in community colleges or in K-12 settings," Schneider said in a statement on the evaluation. "WestEd looks forward to evaluating the effectiveness of Khan Academy's resources in improving community college students' algebra achievement."