Two professors’ “cage match” debate over key issues facing MOOC developers was an antidote to the button-down manner of the business leaders at other sessions.

Austin, Tex. — Who should lead innovation in education—teachers or entrepreneurs? That key question was in the air here at this year’s South by Southwest Edu conference, which brought together a mix of entrepreneurs and educators for four days of panels and a competition for education start-ups.

In the keynote address on Thursday, Bill Gates, co-chair of the Bill & Melinda Gates Foundation, made the case for why more venture capitalists and businesses should invest in building education products and services to kick-start new ways of teaching with technology. He displayed a chart showing a recent rise in such investment but noted that education still accounts for only 1 percent of all venture-capital investment.

“If you’d have to say what is the sector of the economy you’d like to see the most R&D, you’d think that education would be a very high R&D sector. But it never has been,” Mr. Gates said. “We’re going to have to grow this.”

He said the key would be developing a “gold standard of proving that something works,” and finding better ways for schools and colleges to share real-time data on student performance.

Then Mr. Gates, who is one of the world’s richest men and whose foundation gives hundreds of millions of dollars each year to education projects, brought onstage a school-system leader and two chief executives of education companies to talk about their efforts.

The companies, DreamBox Learning and InBloom, focus on secondary-school students, but Mr. Gates also mentioned MOOCs, or massive open online courses, as an important innovation at the college level.

During the talk, some participants tweeted their frustration with the strong focus on business: “Is he really interviewing CEOs?! Why not educators?” wrote one school principal.

Some sessions led by professors at the conference also expressed a skepticism of businesses’ heightened interests in profiting from education.

In a colorful session just before Mr. Gates spoke, two professors who have taught MOOCs presented what was billed as a “cage match” debate about key issues facing developers of free online courses. It was full of theatrics: Both men donned boxing gloves and protective headgear at times, and the winner pretended to punch the loser after each round, based on voting by audience members, who held up red or blue index cards to signal which of the two professors they thought had made the best arguments.

The professors, who were clearly enjoying themselves, presented an antidote to the button-down manner of the business leaders Mr. Gates brought onstage.

One of the dueling professors, Charles Severance, a clinical associate professor of information at the University of Michigan at Ann Arbor, said he gets a “creepy feeling” when he senses someone is trying primarily to make money from online education. The other debater, Curtis J. Bonk, a professor of education at Indiana University at Bloomington, said he worries that MOOC providers could end up selling student data to companies that are “soliciting things you didn’t mean to be getting.”

That sentiment was echoed by some attendees as well.

“This whole conference has been about technology and all these great entrepreneurs and start-ups. But who said let’s get the students fired up?” asked John Boyer, who teaches large classes at Virginia Tech, in an interview as the event was ending. “We’re all starting to lose sight of what education is all about, which is inspiring students.”

Such tensions didn’t bother the event’s organizers, though. “Frankly, we like that tension,” said Ron Reed, executive producer of the conference. About 30 percent of this year’s 5,000 attendees came from colleges, 30 percent from elementary and secondary education, and 30 percent from businesses and policy groups, he said. “By mixing it up, inevitably you get that tension.”

Many participants applauded the interest of companies, it should be noted, and some said that at a time when many state governments are cutting spending on education, new players will need to find ways to support their efforts. “Even nonprofits have to pay their employees,” noted Alexei V. Filippenko, a professor of astronomy at the University of California at Berkeley who spoke on how to teach large classes and who said he had come to the conference to learn more about MOOCs.

This is the third year of the education event, which has doubled in size each year. It comes just before the larger and longer-running South by Southwest music, film, and interactive festival, which starts on Friday.