“One of our country’s most prestigious universities feels comfortable putting its considerable prestige and brand behind it.” As virtual schooling continues to successfully adapt around traditional face-to-face learning – being both an alternative and an aid – some see Stanford’s move as a sign that the line between secondary and higher education is beginning to blur. About 275,000 students nationwide are enrolled full time in online schools, according to Susan Patrick, president of the International Association for K-12 Online Learning, a nonprofit advocacy group. Most of these are free public charter schools, but colleges have begun to get into the business as well. Several other universities, alongside Stanford, have already begun to operate online high school divisions, a development that has raised some questions about expertise and motives. The University of Nebraska, Lincoln, and the University of Missouri have awarded diplomas to about 250 and 85 students, respectively, annually for the last several years. The George Washington University Online High School opened in January. The program can help spread the expertise of certain colleges – capitalizing on its reputation in foreign language instruction, Middlebury College in Vermont last year worked with K12, a for-profit company, to develop online high school language courses serving 50,000 students nationwide. Ronald Liebowitz, Middlebury’s president, said that while “it looks like mission creep beyond belief,” the opportunity to raise revenue carried the decision, as Middlebury gets a cut of the profits from every $749 each student pays per year. Mr. Liebowitz is aware of the risk of lending Middlebury’s name to a program whose teachers are not affiliated with the college, but: “We could have millions of dollars coming into the operating budget, which eases the burden of other revenue streams — mainly tuition and other fees. It’s a for-profit venture.” In such a growing market, Stanford Online High School aims to be the destination for the most talented students, as still being able to attract hordes of gifted pupils with just its name alone. About 20 percent of the current 120 students receive financial aid to offset the $14,800 tuition, which is about half the average private-school tuition nationwide but far more than the University of Nebraska program’s $2,500. About 300 more students take one or more $3,200-per-year classes to supplement a bricks-and-mortar program.