By Anya Kamenetz, The Hechinger Report

A Bay Area nonprofit called the Learning Accelerator (TLA), started with funds from the Bill & Melinda Gates Foundation, has just scored a $5 million grant to expand its operations greatly and get more blended learning programs into more K-12 schools. (Note: The Gates Foundation is among the various funders of The Hechinger Report.)

“Blended learning is the transformative educational innovation of our time and has the potential to significantly improve K-12 education for all students across the country,” Joe Wolf, president and founding board member of TLA, said.

Is this true? Is blended learning the transformative educational innovation of our time? Research tends to support the idea that when you mix technology into a face-to-face classroom setting, it improves learning outcomes. But there are caveats that should temper the zealous rhetoric, and offer direction going forward.

For example, here’s a review of over 1,000 of the most rigorous empirical studies from 1996-2008. It shows what the researchers termed “modest” improvement in performance for online learning vs. face-to-face learning. There was a little more improvement in blended conditions rather than all-online. The authors of the analysis caution that blended conditions often included additional time and instructional elements not received by students in control conditions, making a fair comparison impossible. Plus, very few studies looked at K-12 rather than higher education or corporate training, making it difficult to generalize these results to K-12 classrooms.

A separate meta-analysis published in 2011 has the tantalizing title “What Forty Years of Research Says About the Impact of Technology on Learning.” The researchers looked at studies going back to 1985, which is itself a recurring problem in analyzing the effects of technology on teaching and learning: The technology itself is changing literally every few months, and it’s hard to determine what learning software written for the Commodore 64 has in common with, say, augmented-reality mobile apps for beginning readers.

Still, in another analysis of over 1,000 primary studies, each of which compared blended learning to face-to-face, and over 100,000 experimental subjects, researchers found a clear positive trend: a moderate effect size (0.35), supporting the use of tech in the classroom. This analysis, unlike the previous one, showed a larger effect size for K-12 vs. postsecondary students. And interestingly,researchers found “a small but significantly higher average effect size for technology that supportsinstruction over applications that deliver direct instruction, such as computer-assisted instruction” (emphasis mine). In other words: student with laptop, pretty good; teacher with laptop, even better.

Even as the jury deliberates, the trend of online and blended learning in K-12 will continue to accelerate. In the year 2000, roughly 45,000 K–12 students took an all-online course. In 2009, more than 3 million K–12 students did. And by some measures, pretty much all learning is soon going to include some technological element. Every child who does her homework with the help of Wikipedia or YouTube, and every teacher who uses text messaging to keep tabs on her students, is in some sense engaging in “blended learning.” This report on the rise of blended learning identified six models—ranging from completely in-class and driven by face-to-face teaching, to completely online with optional face-to-face check-ins—falling under the broad definition of blended learning.

TLA defines blended learning “as having three core elements: personalized learning, mastery-based progression, and effective application of technology.” Its strategy is to focus on some of the barriers, such as broadband availability, coordination of purchasing across districts and professional development. TLA is begging the question a bit by defining “effectiveness” as part of what blended learning means. Framing its mission this way expresses a commitment to continuing to test, redevelop and redeploy technology to ensure it meets stated goals.

This post was produced by The Hechinger Report, a non-profit journalism organization housed at Columbia University in New York City.