About 116,000 students were educated in 93 virtual schools — those where instruction is entirely or mainly provided over the Internet — run by private management companies in the 2010-11 school year, up 43 percent from the previous year, according to the report being published by the National Education Policy Center, a research center at the University of Colorado. About 27 percent of these schools achieved “adequate yearly progress,” the key federal standard set forth under the No Child Left Behind act to measure academic progress. By comparison, nearly 52 percent of all privately managed brick-and-mortar schools reached that goal, a figure comparable to all public schools nationally. “There’s a pretty large gap between virtual and brick-and-mortar,” said Gary Miron, a professor of evaluation, measurement and research at Western Michigan University and a co-author of the study. “E.M.O.’s” — educational management organizations, a term coined by Wall Street in the 1990s — now operate 35 percent of all charter schools, enrolling 42 percent of all charter school students, according to the report. “Charter schools are publicly funded and they are serving public school students,” Dr. Miron noted. “But they are increasingly privately owned and privately governed.” Some of the management companies are nonprofit organizations — the largest is the KIPP Foundation, with 28,261 students — while others are for-profit companies (K12 Inc. leads this sector, with 65,396). The report focuses on those that have full-service agreements to run schools, as opposed to vendors that offer ancillary services like curriculum development. The number of schools — virtual as well as brick-and-mortar — managed by for-profit E.M.O.’s dropped 2 percent in 2010-11 from the previous year, but the number of students leaped 5 percent to 394,096. In the nonprofit sector, there was a 12 percent increase in the number of schools to 1,170 and a 62 percent increase in students to 384,067. Nonprofit E.M.O.’s have a better track record of academic success than for-profits, and smaller E.M.O.’s in general perform better than larger ones, at least defined by the federal standard of adequate yearly progress — a metric Dr. Miron called “very crude.” Data was not available for about 10 percent of the schools run by for-profit E.M.O.’s and 20 percent of those run by nonprofits. Among those that did provide data, 48 percent of the schools run by for-profits met the federal standard, as did 56 percent of those run by nonprofits. About 52 percent of traditional public schools meet the standard. Among large for-profit E.M.O.’s — those that manage 10 or more schools — 43 percent met the federal progress standard, compared with 62 percent of the schools run by E.M.O.’s with one to three schools. Among nonprofits, 63 percent of those with four to nine schools met the standard, compared with 52 percent for organizations running 10 or more schools and 56 percent for those running one to three.