Also see the three related posts today (below). — Ed.

According to venture capitalists and entrepreneurs,  technology will “disrupt” education as we know it, and maybe create a few billion-dollar companies along the way (see “The Crisis in Higher Education”), says Technology Review.

According to Dow Jones VentureSource, VCs invested $217 million in digital education companies during the first half of 2012 — more than they did during all of 2010. The explosion of new companies is creating a complex environment, as this map of the dozens of technology companies active in K-12 schools makes clear.

So which of these startups will end up mattering? Today, the venture firm Union Square Ventures took the unusual step of blogging about its “investment thesis” in online education. Union Square’s bottom line: the best investments will be companies that give educational content away for free.

To accompany its analysis of the education market, Union Square provided a reading list of news articles whose arguments it apparently found persuasive.

However, Union Square says that unless people can turn “free” online courses into an actual academic credential, or into a career, digital education will remain “aspirational and removed from the day-to-day of many people.”